Merge remote-tracking branch 'origin/main' into feat/knowledge-retrieval-core

# Conflicts:
#	README.md
#	backend/app/routes.py
#	docs/architecture/AI笔记软件技术栈说明-团队版-v2.3.md
#	docs/development/Knowledge与Retrieval-Core开发说明.md

backend/tests/test_api.py

@@ -1,26 +1,12 @@
 import asyncio
+import threading
+from types import SimpleNamespace
+
+import pytest
 
-from app.main import health, service_status
-from app.routes import (
-    get_index_status,
-    list_notes,
-    list_plugins,
-    list_provider_presets,
-    list_providers,
-    list_skills,
-)
-from app.routes import (
-    create_provider,
-    create_task,
-    delete_provider,
-    delete_task,
-    get_provider,
-    get_task,
-    list_tasks,
-    update_provider,
-    update_task,
-)
 from app.contracts import (
+    McpServerSecretStatus,
+    McpServerSecretWriteRequest,
     ProviderCreateRequest,
     ProviderType,
     ProviderUpdateRequest,
@@ -28,6 +14,61 @@ from app.contracts import (
     TaskStatus,
     TaskUpdateRequest,
 )
+from app.main import health, service_status
+from app.routes import (
+    create_provider,
+    create_task,
+    delete_provider,
+    delete_task,
+    get_index_status,
+    get_provider,
+    get_task,
+    list_notes,
+    list_plugins,
+    list_provider_presets,
+    list_providers,
+    list_skills,
+    list_tasks,
+    update_provider,
+    update_task,
+)
+
+
+def test_mcp_secret_routes_offload_blocking_lifecycle_work(monkeypatch) -> None:
+    from app import routes
+
+    caller_thread = threading.get_ident()
+    worker_threads: list[int] = []
+
+    class FakeMcpRegistry:
+        def put_secret(self, server_id, key, secret, *, kind):
+            worker_threads.append(threading.get_ident())
+            return McpServerSecretStatus(key=key, configured=True)
+
+        def delete_secret(self, server_id, key, *, kind):
+            worker_threads.append(threading.get_ident())
+            return McpServerSecretStatus(key=key, configured=False)
+
+    monkeypatch.setattr(
+        routes,
+        "container",
+        SimpleNamespace(mcp_servers=FakeMcpRegistry()),
+    )
+    written = asyncio.run(
+        routes.put_mcp_server_secret(
+            "server-1",
+            "TOKEN",
+            McpServerSecretWriteRequest(secret="hidden"),
+            kind="environment",
+        )
+    )
+    deleted = asyncio.run(
+        routes.delete_mcp_server_secret("server-1", "TOKEN", kind="environment")
+    )
+
+    assert written.configured is True
+    assert deleted.configured is False
+    assert worker_threads and all(item != caller_thread for item in worker_threads)
 
 
 def test_health() -> None:
@@ -36,6 +77,172 @@ def test_health() -> None:
     assert response.model_dump() == {"status": "ok"}
 
 
+def test_mcp_create_and_trust_are_not_executed_on_event_loop(monkeypatch) -> None:
+    from app import routes
+    from app.contracts import McpServerCreateRequest, McpServerTrustRequest
+
+    caller = threading.get_ident()
+    workers = []
+
+    class Registry:
+        def create(self, request):
+            workers.append(threading.get_ident())
+            return "created"
+
+        def trust(self, server_id, digest):
+            workers.append(threading.get_ident())
+            return "trusted"
+
+    monkeypatch.setattr(routes, "container", SimpleNamespace(mcp_servers=Registry()))
+    assert (
+        asyncio.run(
+            routes.create_mcp_server(McpServerCreateRequest(name="test", command="uvx"))
+        )
+        == "created"
+    )
+    assert (
+        asyncio.run(
+            routes.trust_mcp_server(
+                "test", McpServerTrustRequest(command_digest="a" * 64)
+            )
+        )
+        == "trusted"
+    )
+    assert len(workers) == 2
+    assert all(worker != caller for worker in workers)
+
+
+def test_mcp_split_config_and_secret_requests_persist_without_plaintext(
+    monkeypatch,
+) -> None:
+    from fastapi.testclient import TestClient
+
+    from app import routes
+    from app.agent.tools import ToolRegistry
+    from app.config import get_settings
+    from app.extensions.mcp_registry import McpServerRegistry
+    from app.main import app
+    from app.providers.credentials import EncryptedCredentialStore
+
+    service = McpServerRegistry(
+        ToolRegistry(),
+        EncryptedCredentialStore(),
+        get_settings().data_dir,
+        allow_process_launch=True,
+    )
+    monkeypatch.setattr(routes, "container", SimpleNamespace(mcp_servers=service))
+    client = TestClient(app)
+    config = {
+        "name": "MiniMax configuration test",
+        "command": "uvx",
+        "environment": {"MINIMAX_API_HOST": "https://api.minimaxi.com"},
+        "secret_environment_keys": ["MINIMAX_API_KEY"],
+        "startup_timeout_seconds": 120,
+        "tool_timeout_seconds": 300,
+    }
+    # Reproduce the old frontend payload. The backend still enforces separation.
+    invalid = client.post(
+        "/api/mcp/servers",
+        json={
+            **config,
+            "environment": {
+                **config["environment"],
+                "MINIMAX_API_KEY": "synthetic-only",
+            },
+        },
+    )
+    assert invalid.status_code == 422
+    assert invalid.json()["error"]["code"] == "MCP_ENVIRONMENT_INVALID"
+    created = client.post("/api/mcp/servers", json=config)
+    assert created.status_code == 201
+    server_id = created.json()["server_id"]
+    saved = client.put(
+        f"/api/mcp/servers/{server_id}/secrets/MINIMAX_API_KEY",
+        json={"secret": "synthetic-only"},
+    )
+    assert saved.status_code == 200
+    current = client.get(f"/api/mcp/servers/{server_id}")
+    assert current.json()["secret_environment"] == {"MINIMAX_API_KEY": True}
+    assert "synthetic-only" not in current.text
+    assert "synthetic-only" not in service._path.read_text(encoding="utf-8")
+    _, credentials_path = service.credentials._paths()
+    assert "synthetic-only" not in credentials_path.read_text(encoding="utf-8")
+    assert not current.json()["enabled"]  # Saving never starts a third-party process.
+    client.close()
+
+
+@pytest.mark.parametrize("operation", ["create", "trust"])
+def test_mcp_lifecycle_lock_contention_keeps_event_loop_responsive(
+    monkeypatch,
+    operation,
+) -> None:
+    from app import routes
+    from app.agent.tools import ToolRegistry
+    from app.config import get_settings
+    from app.contracts import McpServerCreateRequest, McpServerTrustRequest
+    from app.extensions.mcp_registry import McpServerRegistry
+    from app.providers.credentials import EncryptedCredentialStore
+
+    service = McpServerRegistry(
+        ToolRegistry(),
+        EncryptedCredentialStore(),
+        get_settings().data_dir,
+        allow_process_launch=True,
+    )
+    request = McpServerCreateRequest(
+        name="Lock contention fixture", command="not-executed"
+    )
+    server = service.create(request)
+    monkeypatch.setattr(routes, "container", SimpleNamespace(mcp_servers=service))
+    entered = threading.Event()
+    locked = threading.Event()
+    release = threading.Event()
+    original = getattr(service, operation)
+
+    def observed(*args):
+        entered.set()
+        return original(*args)
+
+    def hold_lifecycle_lock():
+        with service._lifecycle_lock:
+            locked.set()
+            release.wait(timeout=5)
+
+    monkeypatch.setattr(service, operation, observed)
+    holder = threading.Thread(target=hold_lifecycle_lock, daemon=True)
+    holder.start()
+    # An independent watchdog lets the test fail rather than hang if a regression
+    # blocks the event loop itself (an asyncio timeout alone cannot catch that).
+    watchdog = threading.Timer(5, release.set)
+    watchdog.start()
+
+    async def exercise():
+        pending = asyncio.create_task(
+            routes.create_mcp_server(request)
+            if operation == "create"
+            else routes.trust_mcp_server(
+                server.server_id,
+                McpServerTrustRequest(command_digest=server.command_digest),
+            )
+        )
+        try:
+            assert await asyncio.to_thread(entered.wait, 2)
+            assert not pending.done()
+            assert not release.is_set()
+            assert (await health()).status == "ok"
+        finally:
+            release.set()
+            await pending
+
+    try:
+        assert locked.wait(timeout=2)
+        asyncio.run(exercise())
+    finally:
+        release.set()
+        watchdog.cancel()
+        holder.join(timeout=2)
+
+
 def test_service_status() -> None:
     response = asyncio.run(service_status())
 
@@ -52,7 +259,9 @@ def test_core_collections_are_typed() -> None:
 
     assert notes.items == []
     assert notes.page.limit == 20
-    assert [skill.manifest.skill_id for skill in skills.items] == ["knowledge-assistant"]
+    assert [skill.manifest.skill_id for skill in skills.items] == [
+        "knowledge-assistant"
+    ]
     assert skills.items[0].status == "ready"
     assert [plugin.manifest.plugin_id for plugin in plugins.items] == ["text-tools"]
     assert plugins.items[0].status == "ready"
@@ -73,9 +282,15 @@ def test_provider_presets_include_openai_and_deepseek() -> None:
 def test_provider_presets_static_route_precedes_provider_id_route() -> None:
     from app.routes import router
 
-    get_paths = [route.path for route in router.routes if "GET" in getattr(route, "methods", set())]
+    get_paths = [
+        route.path
+        for route in router.routes
+        if "GET" in getattr(route, "methods", set())
+    ]
 
-    assert get_paths.index("/api/providers/presets") < get_paths.index("/api/providers/{provider_id}")
+    assert get_paths.index("/api/providers/presets") < get_paths.index(
+        "/api/providers/{provider_id}"
+    )
 
 
 def test_openapi_contains_documented_frontend_interfaces() -> None:
@@ -95,8 +310,20 @@ def test_openapi_contains_documented_frontend_interfaces() -> None:
         "/api/plugins/install",
         "/api/plugins/{plugin_id}/host",
         "/api/plugins/{plugin_id}/host/restart",
+        "/api/plugin-contributions/commands",
+        "/api/plugin-contributions/commands/{command_id}/execute",
+        "/api/plugins/{plugin_id}/settings",
+        "/api/plugins/{plugin_id}/settings/{key}/secret",
         "/api/plugins/{plugin_id}/enable",
         "/api/plugins/{plugin_id}/disable",
+        "/api/mcp/servers",
+        "/api/mcp/servers/{server_id}",
+        "/api/mcp/servers/{server_id}/tools",
+        "/api/mcp/servers/{server_id}/trust",
+        "/api/mcp/servers/{server_id}/test",
+        "/api/mcp/servers/{server_id}/enable",
+        "/api/mcp/servers/{server_id}/disable",
+        "/api/mcp/servers/{server_id}/secrets/{key}",
         "/api/providers/test",
         "/api/providers/presets",
         "/api/credentials/{credential_id}",

backend/tests/test_credentials.py

@@ -1,16 +1,21 @@
 import asyncio
+from pathlib import Path
 
 import httpx
+import pytest
 
 from app.config import get_settings
 from app.contracts import CredentialWriteRequest
+from app.errors import ApiError
 from app.providers.credentials import (
     ChainedCredentialResolver,
+    CredentialStoreError,
     EncryptedCredentialStore,
     EnvironmentCredentialResolver,
 )
+from app.providers.factory import ProviderFactory
 from app.providers.openai_compatible import OpenAICompatibleProvider
-from app.routes import get_credential_status, put_credential
+from app.routes import delete_credential, get_credential_status, put_credential
 
 
 def test_encrypted_credential_store_round_trip_without_plaintext_on_disk() -> None:
@@ -31,6 +36,33 @@ def test_encrypted_credential_store_round_trip_without_plaintext_on_disk() -> No
     assert store.resolve("deepseek") is None
 
 
+def test_encrypted_credential_store_deletes_multiple_credentials_atomically() -> None:
+    store = EncryptedCredentialStore()
+    store.put("plugin.first", "first")
+    store.put("plugin.second", "second")
+    store.put("openai", "keep")
+
+    removed = store.delete_many(["plugin.first", "plugin.second"])
+
+    assert removed == {"plugin.first", "plugin.second"}
+    assert store.resolve("plugin.first") is None
+    assert store.resolve("plugin.second") is None
+    assert store.resolve("openai") == "keep"
+
+
+def test_credential_write_os_error_uses_stable_store_error(monkeypatch) -> None:
+    store = EncryptedCredentialStore()
+    store.put("existing", "value")
+
+    def fail_replace(_path: Path, _target: Path) -> Path:
+        raise OSError("injected replace failure")
+
+    monkeypatch.setattr(Path, "replace", fail_replace)
+
+    with pytest.raises(CredentialStoreError, match="cannot be written"):
+        store.put("new", "value")
+
+
 def test_credential_api_never_returns_secret() -> None:
     written = asyncio.run(
         put_credential(
@@ -72,3 +104,29 @@ def test_saved_credential_takes_precedence_over_environment_fallback(monkeypatch
     resolver = ChainedCredentialResolver(store, EnvironmentCredentialResolver())
 
     assert resolver.resolve("deepseek") == "saved-key"
+
+
+def test_public_credential_api_rejects_plugin_namespace() -> None:
+    operations = [
+        get_credential_status("plugin.text-tools.api_key"),
+        put_credential(
+            "plugin.text-tools.api_key",
+            CredentialWriteRequest(api_key="must-not-write"),
+        ),
+        delete_credential("plugin.text-tools.api_key"),
+    ]
+    for operation in operations:
+        with pytest.raises(ApiError) as exc:
+            asyncio.run(operation)
+        assert exc.value.code == "CREDENTIAL_NAMESPACE_RESERVED"
+
+    assert EncryptedCredentialStore().resolve("plugin.text-tools.api_key") is None
+
+
+def test_provider_resolver_cannot_read_plugin_secret() -> None:
+    store = EncryptedCredentialStore()
+    store.put("plugin.text-tools.api_key", "private-plugin-secret")
+    resolver = ProviderFactory(store).credentials
+
+    with pytest.raises(CredentialStoreError, match="reserved for Plugin settings"):
+        resolver.resolve("plugin.text-tools.api_key")

backend/tests/test_extension_core.py

@@ -11,12 +11,16 @@ from app.container import build_container
 from app.contracts import (
     AgentRunCreateRequest,
     AgentRunStatus,
+    PluginCommandContext,
     SkillStatus,
     ToolCall,
 )
 from app.extensions import ExtensionError
 from app.extensions.mcp import McpStdioClient
-from app.extensions.runtime import _arguments_model_from_schema
+from app.extensions.runtime import (
+    _arguments_model_from_schema,
+    _validate_mcp_command_target_schema,
+)
 from app.services import note_service
 from app.config import BACKEND_DIR, get_settings
 
@@ -33,7 +37,7 @@ def mcp_container():
     container = build_container()
     installed = container.plugins.install(MCP_FIXTURE)
     assert installed.status == "permission_required"
-    container.plugins.set_permissions("mcp-fixture", ["notes.read"])
+    container.plugins.set_permissions("mcp-fixture", ["notes.read", "secrets.use"])
     try:
         yield container
     finally:
@@ -349,7 +353,7 @@ def test_mcp_stdio_host_discovers_namespaced_tools_and_maps_results(
             ToolExecutionContext(run_id="run_mcp_fixture"),
         )
 
-        assert status.tools_count == 6
+        assert status.tools_count == 7
         assert status.protocol_version == "2025-11-25"
         assert status.server_name == "notesagent-mcp-fixture"
         assert definition.permission == "notes.read"
@@ -396,6 +400,162 @@ def test_mcp_stdio_host_discovers_namespaced_tools_and_maps_results(
     run(scenario())
 
 
+def test_mcp_command_target_receives_scoped_context_and_declared_secret(
+    mcp_container,
+) -> None:
+    async def scenario() -> None:
+        mcp_container.plugins.enable("mcp-fixture")
+
+        assert not mcp_container.tools.contains("mcp-fixture.command")
+        with pytest.raises(ExtensionError) as missing:
+            await mcp_container.plugins.execute_command(
+                "mcp-fixture.notify",
+                {},
+                PluginCommandContext(selection="来自选区"),
+            )
+        assert missing.value.code == "PLUGIN_SECRET_REQUIRED"
+
+        mcp_container.plugins.put_setting_secret(
+            "mcp-fixture", "api_key", "mcp-command-secret"
+        )
+        mcp_container.plugins.update_settings(
+            "mcp-fixture", 1, {"message_prefix": "Fixture: "}
+        )
+        result = await mcp_container.plugins.execute_command(
+            "mcp-fixture.notify",
+            {},
+            PluginCommandContext(
+                note_id="must-not-enter-envelope",
+                selection="来自选区",
+            ),
+        )
+
+        assert result.effect.type == "notification"
+        assert result.effect.payload.model_dump() == {
+            "level": "success",
+            "message": "Fixture: 来自选区",
+        }
+        assert "mcp-command-secret" not in repr(
+            mcp_container.plugins.commands.audit_events()
+        )
+
+    run(scenario())
+
+
+def test_mcp_command_target_rejects_incompatible_envelope_schema(tmp_path) -> None:
+    package = tmp_path / "mcp-bad-command"
+    shutil.copytree(MCP_FIXTURE, package)
+    for filename in ("plugin.yaml", "commands.yaml", "settings.yaml"):
+        path = package / filename
+        path.write_text(
+            path.read_text(encoding="utf-8").replace(
+                "mcp-fixture", "mcp-bad-command"
+            ),
+            encoding="utf-8",
+        )
+    server_path = package / "server.py"
+    server_path.write_text(
+        server_path.read_text(encoding="utf-8").replace(
+            '{"_notesagent": {"type": "object"}}',
+            '{"unexpected": {"type": "string"}}',
+        ),
+        encoding="utf-8",
+    )
+    container = build_container()
+    container.plugins.install(package)
+    container.plugins.set_permissions(
+        "mcp-bad-command", ["notes.read", "secrets.use"]
+    )
+    try:
+        with pytest.raises(ExtensionError) as exc:
+            container.plugins.enable("mcp-bad-command")
+        assert exc.value.code == "PLUGIN_CONTRIBUTION_INVALID"
+        assert container.plugins.get("mcp-bad-command").status == "error"
+    finally:
+        container.plugins.shutdown()
+
+
+def test_mcp_command_target_enable_check_only_requires_protocol_marker() -> None:
+    # `not`/`oneOf` 等完整语义由实际调用前的官方 Validator 处理；启用检查
+    # 只确认不可被引用或组合隐藏的稳定宿主入口，避免维护不完整的求解器。
+    _validate_mcp_command_target_schema(
+        {
+            "type": "object",
+            "properties": {
+                "_notesagent": {
+                    "type": "object",
+                    "not": {"type": "object"},
+                }
+            },
+        },
+        "marker.run",
+    )
+
+    invalid_markers = [
+        {
+            "$defs": {"envelope": {"type": "object"}},
+            "properties": {"_notesagent": {"$ref": "#/$defs/envelope"}},
+        },
+        {
+            "allOf": [
+                {"properties": {"_notesagent": {"type": "object"}}},
+            ]
+        },
+    ]
+    for schema in invalid_markers:
+        with pytest.raises(ExtensionError) as exc:
+            _validate_mcp_command_target_schema(schema, "marker.run")
+        assert exc.value.code == "PLUGIN_CONTRIBUTION_INVALID"
+
+
+def test_mcp_command_validates_actual_envelope_before_call(tmp_path) -> None:
+    package = tmp_path / "mcp-runtime-schema"
+    shutil.copytree(MCP_FIXTURE, package)
+    for filename in ("plugin.yaml", "commands.yaml", "settings.yaml"):
+        path = package / filename
+        path.write_text(
+            path.read_text(encoding="utf-8").replace(
+                "mcp-fixture", "mcp-runtime-schema"
+            ),
+            encoding="utf-8",
+        )
+    server_path = package / "server.py"
+    server_path.write_text(
+        server_path.read_text(encoding="utf-8").replace(
+            '{"_notesagent": {"type": "object"}}',
+            '{"_notesagent": {"type": "object", "properties": '
+            '{"arguments": {"type": "object", "maxProperties": 0}, '
+            '"context": {"type": "object", "properties": '
+            '{"selection": {"type": "string"}}, "required": ["selection"]}}, '
+            '"required": ["arguments", "context"]}}',
+        ),
+        encoding="utf-8",
+    )
+    container = build_container()
+    container.plugins.install(package)
+    container.plugins.set_permissions(
+        "mcp-runtime-schema", ["notes.read", "secrets.use"]
+    )
+    try:
+        # context.selection 是 Command 的 when/context 契约保证的真实字段；
+        # 启用期结构检查不得因没有伪造该业务值而拒绝目标 Schema。
+        container.plugins.enable("mcp-runtime-schema")
+        container.plugins.put_setting_secret(
+            "mcp-runtime-schema", "api_key", "configured"
+        )
+        with pytest.raises(ExtensionError) as exc:
+            run(
+                container.plugins.execute_command(
+                    "mcp-runtime-schema.notify",
+                    {"message": "must be rejected locally"},
+                    PluginCommandContext(selection="visible"),
+                )
+            )
+        assert exc.value.code == "PLUGIN_COMMAND_TARGET_SCHEMA_MISMATCH"
+    finally:
+        container.plugins.shutdown()
+
+
 def test_agent_calls_mcp_tool_through_registry_and_writes_trace(mcp_container) -> None:
     async def scenario() -> None:
         mcp_container.plugins.enable("mcp-fixture")
@@ -531,7 +691,7 @@ def test_production_rejects_unsandboxed_mcp_host(monkeypatch) -> None:
     container = build_container()
     installed = container.plugins.install(MCP_FIXTURE)
     assert installed.status == "permission_required"
-    container.plugins.set_permissions("mcp-fixture", ["notes.read"])
+    container.plugins.set_permissions("mcp-fixture", ["notes.read", "secrets.use"])
     try:
         with pytest.raises(ExtensionError) as exc:
             container.plugins.enable("mcp-fixture")
@@ -565,7 +725,7 @@ def test_mcp_abnormal_exit_unregisters_tools_and_restart_recovers(mcp_container)
 
         restarted = mcp_container.plugins.restart_host("mcp-fixture")
         assert restarted.status == "ready"
-        assert restarted.tools_count == 6
+        assert restarted.tools_count == 7
         assert mcp_container.tools.contains("mcp-fixture.echo")
 
     run(scenario())

backend/tests/test_mcp_registry.py

@@ -0,0 +1,769 @@
+import asyncio
+import hashlib
+import json
+import sys
+import threading
+import time
+from concurrent.futures import ThreadPoolExecutor
+
+import httpx
+import pytest
+
+from app.agent.tools import ToolExecutionContext, ToolRegistry
+from app.config import BACKEND_DIR, get_settings
+from app.contracts import McpServerCreateRequest, McpServerUpdateRequest, ToolCall
+from app.extensions.mcp import McpLegacySseClient
+from app.extensions.mcp_registry import McpRegistryError, McpServerRegistry
+from app.providers.credentials import CredentialStoreError, EncryptedCredentialStore
+
+SERVER = BACKEND_DIR / "extensions" / "fixtures" / "mcp-echo" / "server.py"
+
+
+def request(**overrides) -> McpServerCreateRequest:
+    values = {
+        "name": "Echo MCP",
+        "command": sys.executable,
+        "args": [str(SERVER)],
+        "permissions": ["notes.read", "secrets.use"],
+        "secret_environment_keys": ["TEST_MCP_SECRET"],
+    }
+    values.update(overrides)
+    return McpServerCreateRequest(**values)
+
+
+def registry(*, launch: bool = True) -> McpServerRegistry:
+    return McpServerRegistry(
+        ToolRegistry(),
+        EncryptedCredentialStore(),
+        get_settings().data_dir,
+        allow_process_launch=launch,
+    )
+
+
+def test_registry_requires_current_trust_and_never_returns_secret() -> None:
+    service = registry()
+    created = service.create(request())
+    assert created.trusted is False
+    assert created.secret_environment == {"TEST_MCP_SECRET": False}
+
+    service.put_secret(created.server_id, "TEST_MCP_SECRET", "do-not-return")
+    configured = service.get(created.server_id)
+    assert configured.secret_environment == {"TEST_MCP_SECRET": True}
+    assert "do-not-return" not in configured.model_dump_json()
+
+    with pytest.raises(McpRegistryError, match="approve"):
+        service.test(created.server_id)
+
+    service.trust(created.server_id, created.command_digest)
+    tested = service.test(created.server_id)
+    assert tested.status == "stopped"
+    assert tested.last_test_succeeded is True
+    assert tested.tools_count > 0
+    service.shutdown()
+
+
+def test_secret_change_disables_server_and_requires_a_new_connection_test() -> None:
+    service = registry()
+    created = service.create(request())
+    service.put_secret(created.server_id, "TEST_MCP_SECRET", "first")
+    service.trust(created.server_id, created.command_digest)
+    service.test(created.server_id)
+    service.enable(created.server_id)
+
+    service.put_secret(created.server_id, "TEST_MCP_SECRET", "second")
+    current = service.get(created.server_id)
+    assert current.enabled is False
+    assert current.last_test_succeeded is None
+    assert not any(
+        item.name.startswith(f"mcp.{created.server_id}.")
+        for item in service.tools.definitions()
+    )
+    with pytest.raises(McpRegistryError) as error:
+        service.enable(created.server_id)
+    assert error.value.code == "MCP_CONNECTION_TEST_REQUIRED"
+    service.shutdown()
+
+
+def test_update_disables_server_and_revokes_command_trust() -> None:
+    service = registry()
+    created = service.create(request(secret_environment_keys=[]))
+    service.trust(created.server_id, created.command_digest)
+    service.test(created.server_id)
+    enabled = service.enable(created.server_id)
+    assert enabled.enabled is True
+    assert any(
+        item.name.startswith(f"mcp.{created.server_id}.")
+        for item in service.tools.definitions()
+    )
+
+    updated = service.update(
+        created.server_id,
+        McpServerUpdateRequest(
+            **request(name="Changed", secret_environment_keys=[]).model_dump(),
+            version=enabled.version,
+        ),
+    )
+    assert updated.enabled is False
+    assert updated.trusted is False
+    assert not any(
+        item.name.startswith(f"mcp.{created.server_id}.")
+        for item in service.tools.definitions()
+    )
+    service.shutdown()
+
+
+def test_update_remains_retryable_when_removed_secret_cleanup_fails(
+    monkeypatch,
+) -> None:
+    service = registry()
+    created = service.create(request())
+    service.put_secret(created.server_id, "TEST_MCP_SECRET", "keep-until-retry")
+
+    def fail_delete_many(_secret_ids: list[str]) -> set[str]:
+        raise CredentialStoreError("credential store unavailable")
+
+    monkeypatch.setattr(service.credentials, "delete_many", fail_delete_many)
+    with pytest.raises(McpRegistryError) as error:
+        service.update(
+            created.server_id,
+            McpServerUpdateRequest(
+                **request(secret_environment_keys=[]).model_dump(),
+                version=created.version,
+            ),
+        )
+
+    current = service.get(created.server_id)
+    assert error.value.code == "MCP_SECRET_STORE_ERROR"
+    assert current.version == created.version
+    assert current.secret_environment == {"TEST_MCP_SECRET": True}
+    service.shutdown()
+
+
+def test_delete_keeps_server_retryable_when_secret_cleanup_fails(monkeypatch) -> None:
+    service = registry()
+    created = service.create(request())
+    service.put_secret(created.server_id, "TEST_MCP_SECRET", "keep-until-retry")
+
+    def fail_delete_many(_secret_ids: list[str]) -> set[str]:
+        raise CredentialStoreError("credential store unavailable")
+
+    monkeypatch.setattr(service.credentials, "delete_many", fail_delete_many)
+    with pytest.raises(McpRegistryError) as error:
+        service.delete(created.server_id)
+
+    current = service.get(created.server_id)
+    assert error.value.code == "MCP_SECRET_STORE_ERROR"
+    assert current.server_id == created.server_id
+    assert current.secret_environment == {"TEST_MCP_SECRET": True}
+    service.shutdown()
+
+
+def test_unavailable_server_removes_bridge_host(monkeypatch) -> None:
+    service = registry()
+    created = service.create(request(secret_environment_keys=[]))
+    with service._lock:
+        service._records[created.server_id] = {
+            **service._records[created.server_id],
+            "enabled": True,
+        }
+    removed: list[str] = []
+    monkeypatch.setattr(service.bridge, "remove", removed.append)
+
+    generation = object()
+    service._generations[created.server_id] = generation
+    service._unavailable(created.server_id, generation, "connection lost")
+
+    current = service.get(created.server_id)
+    assert removed == [f"mcp.{created.server_id}"]
+    assert current.enabled is False
+    assert current.status == "unhealthy"
+    service.shutdown()
+
+
+def test_old_failure_callback_cannot_stop_replacement_host(monkeypatch) -> None:
+    service = registry()
+    callbacks = []
+    original_start = service.bridge.start
+
+    def capture_callback(*args, **kwargs):
+        callbacks.append(args[4])
+        return original_start(*args, **kwargs)
+
+    monkeypatch.setattr(service.bridge, "start", capture_callback)
+    created = service.create(request(secret_environment_keys=[]))
+    service.trust(created.server_id, created.command_digest)
+    callback_thread = None
+    try:
+        service.test(created.server_id)
+        service.enable(created.server_id)
+        old_callback = callbacks[-1]
+        callback_started = threading.Event()
+        callback_finished = threading.Event()
+
+        def delayed_failure():
+            callback_started.set()
+            old_callback(f"mcp.{created.server_id}", "delayed old failure")
+            callback_finished.set()
+
+        # Queue the old callback while a replacement owns the lifecycle lock.
+        with service._lifecycle_lock:
+            callback_thread = threading.Thread(target=delayed_failure, daemon=True)
+            callback_thread.start()
+            assert callback_started.wait(timeout=2)
+            service.disable(created.server_id)
+            service.enable(created.server_id)
+        assert callback_finished.wait(timeout=2)
+        assert service.get(created.server_id).enabled is True
+        assert service.get(created.server_id).status == "ready"
+        assert service.tools.definitions()
+        callbacks[-1](f"mcp.{created.server_id}", "current failure")
+        assert service.get(created.server_id).enabled is False
+        assert service.get(created.server_id).status == "unhealthy"
+    finally:
+        service.shutdown()
+        if callback_thread is not None:
+            callback_thread.join(timeout=2)
+
+
+def test_header_case_only_rename_preserves_secret() -> None:
+    service = registry()
+    config = {
+        "name": "HTTP",
+        "transport": "streamable_http",
+        "url": "https://example.test/mcp",
+        "secret_header_keys": ["Authorization"],
+    }
+    created = service.create(McpServerCreateRequest(**config))
+    service.put_secret(created.server_id, "Authorization", "synthetic", kind="header")
+    config["secret_header_keys"] = ["authorization"]
+    updated = service.update(
+        created.server_id, McpServerUpdateRequest(**config, version=created.version)
+    )
+    assert updated.secret_headers == {"authorization": True}
+    assert (
+        service.credentials.resolve(
+            service._secret_id(created.server_id, "authorization", "header")
+        )
+        == "synthetic"
+    )
+
+
+def test_environment_secrets_are_case_sensitive_and_delete_independently() -> None:
+    service = registry()
+    created = service.create(request(secret_environment_keys=["TOKEN", "token"]))
+    service.put_secret(created.server_id, "TOKEN", "upper")
+    service.put_secret(created.server_id, "token", "lower")
+    assert (
+        service.credentials.resolve(service._secret_id(created.server_id, "TOKEN"))
+        == "upper"
+    )
+    assert (
+        service.credentials.resolve(service._secret_id(created.server_id, "token"))
+        == "lower"
+    )
+    service.delete_secret(created.server_id, "TOKEN")
+    assert service.get(created.server_id).secret_environment == {
+        "TOKEN": False,
+        "token": True,
+    }
+
+
+def test_legacy_environment_credential_migration_is_idempotent() -> None:
+    service = registry()
+    created = service.create(request(secret_environment_keys=["TOKEN"]))
+    suffix = hashlib.sha256(b"environment\0token").hexdigest()[:20]
+    legacy_id = f"mcp.{created.server_id}.{suffix}"
+    service.credentials.put(legacy_id, "legacy-value")
+    service._records[created.server_id]["secret_environment_version"] = 1
+    service._write()
+    migrated = registry()
+    assert migrated.get(created.server_id).secret_environment == {"TOKEN": True}
+    assert (
+        migrated.credentials.resolve(migrated._secret_id(created.server_id, "TOKEN"))
+        == "legacy-value"
+    )
+    assert not migrated.credentials.has(legacy_id)
+    migrated.put_secret(created.server_id, "TOKEN", "new-value")
+    assert (
+        registry().credentials.resolve(migrated._secret_id(created.server_id, "TOKEN"))
+        == "new-value"
+    )
+
+
+def test_ambiguous_legacy_credentials_are_not_assigned_to_two_variables() -> None:
+    service = registry()
+    created = service.create(request(secret_environment_keys=["TOKEN", "token"]))
+    suffix = hashlib.sha256(b"environment\0token").hexdigest()[:20]
+    legacy_id = f"mcp.{created.server_id}.{suffix}"
+    service.credentials.put(legacy_id, "cannot-reconstruct-originals")
+    service._records[created.server_id]["secret_environment_version"] = 1
+    service._write()
+    migrated = registry()
+    current = migrated.get(created.server_id)
+    assert current.secret_environment == {"TOKEN": False, "token": False}
+    assert current.enabled is False
+    assert current.last_test_succeeded is None
+    assert migrated.credentials.has(
+        legacy_id
+    )  # Keep the original ciphertext recoverable.
+    migrated.put_secret(created.server_id, "TOKEN", "upper")
+    migrated.put_secret(created.server_id, "token", "lower")
+    assert registry().get(created.server_id).secret_environment == {
+        "TOKEN": True,
+        "token": True,
+    }
+    migrated.delete(created.server_id)
+    assert not migrated.credentials.has(legacy_id)
+
+
+def test_credential_id_migration_keeps_new_values_and_is_atomic(monkeypatch) -> None:
+    credentials = EncryptedCredentialStore()
+    credentials.put("mcp.old", "old-value")
+    credentials.put("mcp.new", "new-value")
+    original_write = credentials._write_tokens
+
+    def fail_write(_tokens):
+        raise CredentialStoreError("synthetic failure")
+
+    monkeypatch.setattr(credentials, "_write_tokens", fail_write)
+    with pytest.raises(CredentialStoreError):
+        credentials.move_many({"mcp.old": "mcp.new"})
+    assert credentials.resolve("mcp.old") == "old-value"
+    assert credentials.resolve("mcp.new") == "new-value"
+    monkeypatch.setattr(credentials, "_write_tokens", original_write)
+    credentials.move_many({"mcp.old": "mcp.new"})
+    assert credentials.resolve("mcp.old") is None
+    assert credentials.resolve("mcp.new") == "new-value"
+
+
+def test_ambiguous_legacy_secret_is_not_resurrected_after_removing_a_key() -> None:
+    service = registry()
+    created = service.create(request(secret_environment_keys=["TOKEN", "token"]))
+    legacy_id = service._legacy_environment_secret_id(created.server_id, "TOKEN")
+    service.credentials.put(legacy_id, "ambiguous-old-value")
+    service._records[created.server_id]["secret_environment_version"] = 1
+    service._write()
+    migrated = registry()
+    migrated.update(
+        created.server_id,
+        McpServerUpdateRequest(
+            **request(secret_environment_keys=["token"]).model_dump(),
+            version=created.version,
+        ),
+    )
+    assert registry().get(created.server_id).secret_environment == {"token": False}
+
+
+def test_production_rejects_process_launch_even_after_approval() -> None:
+    service = registry(launch=False)
+    created = service.create(request(secret_environment_keys=[]))
+    service.trust(created.server_id, created.command_digest)
+    with pytest.raises(McpRegistryError) as error:
+        service.enable(created.server_id)
+    assert error.value.code == "MCP_SANDBOX_REQUIRED"
+
+
+@pytest.mark.parametrize("startup,tool", [(120, 300), (1.5, 2.5)])
+def test_server_timeouts_survive_bridge_adaptation_and_reload(startup, tool) -> None:
+    service = registry()
+    created = service.create(
+        request(
+            secret_environment_keys=[],
+            startup_timeout_seconds=startup,
+            tool_timeout_seconds=tool,
+        )
+    )
+    service.trust(created.server_id, created.command_digest)
+    try:
+        tested = service.test(created.server_id)
+        assert tested.last_test_succeeded is True
+        assert tested.startup_timeout_seconds == startup
+        assert tested.tool_timeout_seconds == tool
+        restored = registry().get(created.server_id)
+        assert restored.startup_timeout_seconds == startup
+        assert restored.tool_timeout_seconds == tool
+    finally:
+        service.shutdown()
+
+
+def test_enable_requires_successful_test_and_update_checks_version() -> None:
+    service = registry()
+    created = service.create(request(secret_environment_keys=[]))
+    service.trust(created.server_id, created.command_digest)
+    with pytest.raises(McpRegistryError) as error:
+        service.enable(created.server_id)
+    assert error.value.code == "MCP_CONNECTION_TEST_REQUIRED"
+
+    with pytest.raises(McpRegistryError) as error:
+        service.update(
+            created.server_id,
+            McpServerUpdateRequest(
+                **request(secret_environment_keys=[]).model_dump(), version=99
+            ),
+        )
+    assert error.value.code == "MCP_SERVER_VERSION_CONFLICT"
+
+
+def test_http_transport_rejects_invalid_cross_transport_fields() -> None:
+    service = registry()
+    with pytest.raises(McpRegistryError) as error:
+        service.create(
+            request(
+                transport="streamable_http",
+                url="https://example.invalid/mcp",
+                secret_environment_keys=[],
+            )
+        )
+    assert error.value.code == "MCP_CONFIG_INVALID"
+
+
+def test_registry_rejects_corrupt_persisted_json(tmp_path) -> None:
+    path = tmp_path / "mcp"
+    path.mkdir()
+    (path / "servers.json").write_text("{broken", encoding="utf-8")
+    with pytest.raises(McpRegistryError) as error:
+        McpServerRegistry(
+            ToolRegistry(),
+            EncryptedCredentialStore(),
+            tmp_path,
+            allow_process_launch=True,
+        )
+    assert error.value.code == "MCP_REGISTRY_INVALID"
+
+
+def test_registry_rejects_structurally_invalid_record(tmp_path) -> None:
+    path = tmp_path / "mcp"
+    path.mkdir()
+    (path / "servers.json").write_text(
+        json.dumps({"server-1": {"name": "Broken", "transport": "stdio"}}),
+        encoding="utf-8",
+    )
+    with pytest.raises(McpRegistryError) as error:
+        McpServerRegistry(
+            ToolRegistry(),
+            EncryptedCredentialStore(),
+            tmp_path,
+            allow_process_launch=True,
+        )
+    assert error.value.code == "MCP_REGISTRY_INVALID"
+
+
+def test_registry_rejects_create_before_exceeding_persisted_limit(
+    monkeypatch,
+) -> None:
+    service = registry()
+    service.create(request(name="Only server"))
+    monkeypatch.setattr("app.extensions.mcp_registry._MAX_MCP_SERVERS", 1)
+    with pytest.raises(McpRegistryError) as error:
+        service.create(request(name="One too many"))
+    assert error.value.code == "MCP_SERVER_LIMIT_REACHED"
+    assert len(service.list()) == 1
+    service.shutdown()
+
+
+def test_stdio_command_is_not_parsed_as_a_shell_string() -> None:
+    service = registry()
+    created = service.create(
+        request(
+            command=f'"{sys.executable}" "{SERVER}"',
+            args=[],
+            secret_environment_keys=[],
+        )
+    )
+    service.trust(created.server_id, created.command_digest)
+    with pytest.raises(McpRegistryError) as error:
+        service.test(created.server_id)
+    assert error.value.code == "PLUGIN_HOST_START_FAILED"
+    assert service.get(created.server_id).last_test_succeeded is False
+    service.shutdown()
+
+
+def test_enabled_server_is_restored_from_persisted_registry() -> None:
+    first = registry()
+    created = first.create(request(secret_environment_keys=[]))
+    first.trust(created.server_id, created.command_digest)
+    first.test(created.server_id)
+    first.enable(created.server_id)
+    first.shutdown()
+
+    restored = registry()
+    restored.restore_enabled()
+    current = restored.get(created.server_id)
+    assert current.enabled is True
+    assert current.status == "ready"
+    assert any(
+        item.name.startswith(f"mcp.{created.server_id}.")
+        for item in restored.tools.definitions()
+    )
+    restored.shutdown()
+
+
+def test_lifecycle_operations_are_serialized_and_tool_names_are_isolated() -> None:
+    service = registry()
+    servers = [
+        service.create(request(name=f"Echo {index}", secret_environment_keys=[]))
+        for index in range(2)
+    ]
+    for server in servers:
+        service.trust(server.server_id, server.command_digest)
+        service.test(server.server_id)
+
+    with ThreadPoolExecutor(max_workers=4) as pool:
+        enabled = list(
+            pool.map(lambda item: service.enable(item.server_id), servers * 2)
+        )
+    assert all(item.enabled for item in enabled)
+    names = [
+        item.name for item in service.tools.definitions() if item.source == "mcp_server"
+    ]
+    assert len(names) == len(set(names))
+    assert all(
+        any(name.startswith(f"mcp.{item.server_id}.") for name in names)
+        for item in servers
+    )
+
+    with ThreadPoolExecutor(max_workers=4) as pool:
+        list(pool.map(lambda item: service.disable(item.server_id), servers * 2))
+    assert not any(item.source == "mcp_server" for item in service.tools.definitions())
+    service.shutdown()
+
+
+def _http_result(request_id: int, result: dict) -> httpx.Response:
+    return httpx.Response(
+        200,
+        headers={"content-type": "application/json"},
+        json={"jsonrpc": "2.0", "id": request_id, "result": result},
+    )
+
+
+def test_streamable_http_supports_session_headers_secrets_and_tool_summary(
+    monkeypatch,
+) -> None:
+    requests: list[httpx.Request] = []
+    request_timeouts: dict[str, float] = {}
+
+    def handler(request_value: httpx.Request) -> httpx.Response:
+        requests.append(request_value)
+        if request_value.method == "GET":
+            return httpx.Response(405)
+        if request_value.method == "DELETE":
+            return httpx.Response(405)
+        payload = json.loads(request_value.content)
+        timeout = request_value.extensions.get("timeout", {}).get("read")
+        if isinstance(timeout, (int, float)):
+            request_timeouts[payload.get("method", "notification")] = float(timeout)
+        if payload.get("method") == "initialize":
+            response = _http_result(
+                payload["id"],
+                {
+                    "protocolVersion": "2025-11-25",
+                    "capabilities": {"tools": {}},
+                    "serverInfo": {"name": "HTTP Fixture", "version": "1"},
+                },
+            )
+            response.headers["MCP-Session-Id"] = "session-test"
+            return response
+        if payload.get("method") == "tools/list":
+            return _http_result(
+                payload["id"],
+                {
+                    "tools": [
+                        {
+                            "name": "echo",
+                            "description": "Echo over HTTP",
+                            "inputSchema": {"type": "object", "properties": {}},
+                        }
+                    ]
+                },
+            )
+        if payload.get("method") == "tools/call":
+            return _http_result(
+                payload["id"], {"structuredContent": {"transport": "http"}}
+            )
+        return httpx.Response(202)
+
+    real_client = httpx.Client
+    monkeypatch.setattr(
+        "app.extensions.mcp.httpx.Client",
+        lambda **kwargs: real_client(transport=httpx.MockTransport(handler), **kwargs),
+    )
+    service = registry()
+    created = service.create(
+        McpServerCreateRequest(
+            name="Remote MCP",
+            transport="streamable_http",
+            url="https://mcp.example.test/mcp",
+            headers={"X-Client": "NotesAgent"},
+            secret_header_keys=["Authorization"],
+        )
+    )
+    service.put_secret(
+        created.server_id, "Authorization", "Bearer hidden", kind="header"
+    )
+    service.trust(created.server_id, created.command_digest)
+    tested = service.test(created.server_id)
+
+    assert tested.last_test_succeeded is True
+    assert tested.secret_headers == {"Authorization": True}
+    assert "Bearer hidden" not in tested.model_dump_json()
+    assert service.list_tools(created.server_id)[0].remote_name == "echo"
+    assert any(
+        request.headers.get("mcp-session-id") == "session-test" for request in requests
+    )
+    assert any(
+        request.headers.get("mcp-protocol-version") == "2025-11-25"
+        for request in requests
+    )
+    assert all(
+        request.headers.get("authorization") == "Bearer hidden" for request in requests
+    )
+    assert request_timeouts["initialize"] == 15
+    assert request_timeouts["notifications/initialized"] == 15
+    assert request_timeouts["tools/list"] == 15
+    enabled = service.enable(created.server_id)
+    tool_name = service.list_tools(created.server_id)[0].name
+    result = asyncio.run(
+        service.tools.execute(
+            ToolCall(tool_call_id="call-1", name=tool_name, arguments={}),
+            ToolExecutionContext(run_id="run-1"),
+        )
+    )
+    assert enabled.enabled is True
+    assert result.success is True
+    assert result.output == {"transport": "http"}
+    assert request_timeouts["tools/call"] == 30
+    service.disable(created.server_id)
+    service.shutdown()
+
+
+class _LegacyEventStream(httpx.SyncByteStream):
+    def __init__(self) -> None:
+        self.closed = threading.Event()
+
+    def __iter__(self):
+        yield b"event: endpoint\ndata: /messages\n\n"
+        time.sleep(0.1)
+        initialize = {
+            "jsonrpc": "2.0",
+            "id": 1,
+            "result": {
+                "protocolVersion": "2024-11-05",
+                "capabilities": {"tools": {}},
+                "serverInfo": {"name": "Legacy Fixture"},
+            },
+        }
+        yield f"data: {json.dumps(initialize)}\n\n".encode()
+        time.sleep(0.1)
+        tools = {
+            "jsonrpc": "2.0",
+            "id": 2,
+            "result": {"tools": []},
+        }
+        yield f"data: {json.dumps(tools)}\n\n".encode()
+        self.closed.wait()
+
+    def close(self) -> None:
+        self.closed.set()
+
+
+def test_legacy_sse_uses_same_origin_endpoint(monkeypatch) -> None:
+    posted_urls: list[str] = []
+    event_stream = _LegacyEventStream()
+
+    def handler(request_value: httpx.Request) -> httpx.Response:
+        if request_value.method == "GET":
+            return httpx.Response(
+                200,
+                headers={"content-type": "text/event-stream"},
+                stream=event_stream,
+            )
+        posted_urls.append(str(request_value.url))
+        return httpx.Response(202)
+
+    real_client = httpx.Client
+    monkeypatch.setattr(
+        "app.extensions.mcp.httpx.Client",
+        lambda **kwargs: real_client(transport=httpx.MockTransport(handler), **kwargs),
+    )
+    service = registry()
+    created = service.create(
+        McpServerCreateRequest(
+            name="Legacy MCP",
+            transport="sse",
+            url="https://legacy.example.test/sse",
+        )
+    )
+    service.trust(created.server_id, created.command_digest)
+    tested = service.test(created.server_id)
+    assert tested.last_test_succeeded is True
+    assert posted_urls and all(
+        url == "https://legacy.example.test/messages" for url in posted_urls
+    )
+    service.shutdown()
+    event_stream.close()
+
+
+class _EndingLegacyEventStream(httpx.SyncByteStream):
+    def __iter__(self):
+        yield b"event: endpoint\ndata: /messages\n\n"
+
+
+def test_legacy_sse_eof_marks_client_unavailable(monkeypatch) -> None:
+    def handler(_request_value: httpx.Request) -> httpx.Response:
+        return httpx.Response(
+            200,
+            headers={"content-type": "text/event-stream"},
+            stream=_EndingLegacyEventStream(),
+        )
+
+    real_client = httpx.Client
+    monkeypatch.setattr(
+        "app.extensions.mcp.httpx.Client",
+        lambda **kwargs: real_client(transport=httpx.MockTransport(handler), **kwargs),
+    )
+    broken = threading.Event()
+    client = McpLegacySseClient(
+        "https://legacy.example.test/sse",
+        headers={},
+        startup_timeout_seconds=1,
+        on_seen=lambda: None,
+        on_broken=lambda _message: broken.set(),
+        on_tools_changed=lambda: None,
+    )
+    client.start()
+    assert broken.wait(timeout=1)
+    client.stop()
+
+
+class _CrossOriginLegacyEventStream(httpx.SyncByteStream):
+    def __iter__(self):
+        yield b"event: endpoint\ndata: https://attacker.example/messages\n\n"
+
+
+def test_legacy_sse_rejects_cross_origin_message_endpoint(monkeypatch) -> None:
+    def handler(request_value: httpx.Request) -> httpx.Response:
+        assert request_value.method == "GET"
+        return httpx.Response(
+            200,
+            headers={"content-type": "text/event-stream"},
+            stream=_CrossOriginLegacyEventStream(),
+        )
+
+    real_client = httpx.Client
+    monkeypatch.setattr(
+        "app.extensions.mcp.httpx.Client",
+        lambda **kwargs: real_client(transport=httpx.MockTransport(handler), **kwargs),
+    )
+    service = registry()
+    created = service.create(
+        McpServerCreateRequest(
+            name="Unsafe legacy MCP",
+            transport="sse",
+            url="https://legacy.example.test/sse",
+        )
+    )
+    service.trust(created.server_id, created.command_digest)
+    with pytest.raises(McpRegistryError) as error:
+        service.test(created.server_id)
+    assert error.value.code == "MCP_HTTP_RESPONSE_INVALID"
+    service.shutdown()

backend/tests/test_mcp_sse_limits.py

@@ -0,0 +1,83 @@
+import json
+from contextlib import closing
+
+import httpx
+import pytest
+
+from app.extensions import mcp
+
+
+class ChunkStream(httpx.SyncByteStream):
+    def __init__(self, chunks):
+        self.chunks = chunks
+        self.bytes_read = 0
+
+    def __iter__(self):
+        for chunk in self.chunks:
+            self.bytes_read += len(chunk)
+            yield chunk
+
+
+def test_sse_rejects_unterminated_line_before_reading_entire_stream(monkeypatch):
+    monkeypatch.setattr(mcp, "MAX_MCP_MESSAGE_BYTES", 1024)
+    stream = ChunkStream([b"x" * 256] * 256)
+    with (
+        closing(httpx.Response(200, stream=stream)) as response,
+        pytest.raises(mcp.McpBridgeError, match="too large"),
+    ):
+        list(mcp._iter_sse(response))
+    assert stream.bytes_read == 1280
+
+
+def test_sse_limits_combined_event_before_partial_line_is_complete(monkeypatch):
+    monkeypatch.setattr(mcp, "MAX_MCP_MESSAGE_BYTES", 32)
+    stream = ChunkStream(
+        [b"data: 123456789\n", b"data: 123456789\n", b"x", b"not-read"]
+    )
+    with (
+        closing(httpx.Response(200, stream=stream)) as response,
+        pytest.raises(mcp.McpBridgeError, match="too large"),
+    ):
+        list(mcp._iter_sse(response))
+    assert stream.bytes_read == 33
+
+
+@pytest.mark.parametrize("separator", [b"\n", b"\r", b"\r\n"])
+@pytest.mark.parametrize("chunk_size", [1, 2, 7, 1024])
+def test_sse_preserves_utf8_and_line_endings_across_chunks(separator, chunk_size):
+    payload = json.dumps(
+        {"jsonrpc": "2.0", "id": 1, "result": {"text": "中文"}}, ensure_ascii=False
+    )
+    wire = b"\xef\xbb\xbf" + separator.join(
+        [
+            b": heartbeat",
+            b"event: message",
+            b"id: replay-1",
+            ("data: " + payload).encode(),
+            b"",
+            b"",
+        ]
+    )
+    stream = ChunkStream(
+        [wire[index : index + chunk_size] for index in range(0, len(wire), chunk_size)]
+    )
+    with closing(httpx.Response(200, stream=stream)) as response:
+        assert list(mcp._iter_sse(response)) == [("message", "replay-1", payload)]
+
+
+def test_sse_event_limit_resets_between_events(monkeypatch):
+    monkeypatch.setattr(mcp, "MAX_MCP_MESSAGE_BYTES", 16)
+    with closing(
+        httpx.Response(200, stream=ChunkStream([b"data: one\n\ndata: two\r\r"]))
+    ) as response:
+        assert list(mcp._iter_sse(response)) == [
+            ("message", None, "one"),
+            ("message", None, "two"),
+        ]
+
+
+def test_sse_preserves_multiline_data_and_final_unterminated_line():
+    with closing(
+        httpx.Response(200, stream=ChunkStream([b"data: first\ndata: last"]))
+    ) as response:
+        assert list(mcp._iter_sse(response)) == [("message", None, "first\nlast")]

backend/tests/test_plugin_contributions.py

@@ -0,0 +1,653 @@
+import asyncio
+import json
+from pathlib import Path
+
+import pytest
+from pydantic import TypeAdapter, ValidationError
+
+from app.agent import ToolRegistry
+from app.config import BACKEND_DIR, get_settings
+from app.container import build_container
+from app.contracts import (
+    PluginCommandContext,
+    PluginCommandEffect,
+    PluginNoEffect,
+    PluginSettingType,
+)
+from app.extensions import ExtensionError, PluginRuntime
+from app.extensions.contributions import _secret_reference
+from app.extensions.runtime import DeclarativePluginHost
+from app.providers.credentials import CredentialStoreError
+
+TEXT_TOOLS = BACKEND_DIR / "extensions" / "plugins" / "text-tools"
+
+
+def run(coroutine):
+    return asyncio.run(coroutine)
+
+
+def test_command_list_filter_and_lifecycle() -> None:
+    container = build_container()
+
+    commands = container.plugins.list_commands()
+    palette = container.plugins.list_commands(location="command_palette")
+
+    assert [item.command_id for item in commands] == ["text-tools.uppercase-selection"]
+    assert palette[0].plugin_id == "text-tools"
+    assert palette[0].icon == "edit"
+    assert palette[0].when == ["editor.has_selection"]
+
+    container.plugins.disable("text-tools")
+    assert container.plugins.list_commands() == []
+    with pytest.raises(ExtensionError) as exc:
+        run(
+            container.plugins.execute_command(
+                "text-tools.uppercase-selection",
+                {},
+                PluginCommandContext(selection="hello"),
+            )
+        )
+    assert exc.value.code == "PLUGIN_COMMAND_NOT_FOUND"
+
+    container.plugins.enable("text-tools")
+    assert len(container.plugins.list_commands()) == 1
+
+
+def test_command_executes_with_scoped_context_and_settings() -> None:
+    container = build_container()
+    container.plugins.update_settings("text-tools", 1, {"result_limit": 4})
+
+    result = run(
+        container.plugins.execute_command(
+            "text-tools.uppercase-selection",
+            {},
+            PluginCommandContext(
+                vault_id="default",
+                note_id="note_private",
+                file_path="private.md",
+                selection="abcdef",
+            ),
+        )
+    )
+
+    assert result.status == "completed"
+    assert result.effect.type == "notification"
+    assert result.effect.payload.model_dump() == {
+        "level": "success",
+        "message": "ABCD",
+    }
+
+
+def test_echo_command_returns_none_for_empty_message() -> None:
+    host = DeclarativePluginHost()
+
+    empty = run(host.execute_command("echo", {}, {}, {}, lambda _: None))
+    populated = run(
+        host.execute_command("echo", {"message": "hello"}, {}, {}, lambda _: None)
+    )
+
+    assert isinstance(empty, PluginNoEffect)
+    assert populated.type == "notification"
+    assert populated.payload.message == "hello"
+
+
+@pytest.mark.parametrize(
+    ("effect_type", "payload"),
+    [
+        ("none", {"unexpected": True}),
+        ("notification", {"level": "debug", "message": "invalid"}),
+        ("navigate", {"route": "https://example.com"}),
+        ("refresh", {"scope": "everything"}),
+        ("job", {"job_id": "invalid job id"}),
+    ],
+)
+def test_command_effect_rejects_untrusted_payloads(effect_type, payload) -> None:
+    with pytest.raises(ValidationError):
+        TypeAdapter(PluginCommandEffect).validate_python(
+            {"type": effect_type, "payload": payload}
+        )
+
+
+def test_command_rejects_missing_context_and_invalid_arguments() -> None:
+    container = build_container()
+
+    with pytest.raises(ExtensionError) as context_error:
+        run(
+            container.plugins.execute_command(
+                "text-tools.uppercase-selection", {}, PluginCommandContext()
+            )
+        )
+    assert context_error.value.code == "PLUGIN_COMMAND_CONTEXT_INVALID"
+
+    with pytest.raises(ExtensionError) as argument_error:
+        run(
+            container.plugins.execute_command(
+                "text-tools.uppercase-selection",
+                {"unknown": True},
+                PluginCommandContext(selection="hello"),
+            )
+        )
+    assert argument_error.value.code == "PLUGIN_COMMAND_ARGUMENT_INVALID"
+
+    audit = container.plugins.commands.audit_events()
+    assert [event.error_code for event in audit[-2:]] == [
+        "PLUGIN_COMMAND_CONTEXT_INVALID",
+        "PLUGIN_COMMAND_ARGUMENT_INVALID",
+    ]
+    # 审计事件不得携带参数、正文选区或返回 effect。
+    assert "hello" not in repr(audit)
+
+
+def test_command_only_receives_declared_context() -> None:
+    class CapturingHost(DeclarativePluginHost):
+        def __init__(self) -> None:
+            self.context = None
+
+        async def execute_command(
+            self, handler, arguments, context, settings, resolve_secret
+        ):
+            self.context = context
+            return PluginNoEffect()
+
+    host = CapturingHost()
+    runtime = PluginRuntime(ToolRegistry(), host=host)
+    runtime.install(TEXT_TOOLS)
+    runtime.enable("text-tools")
+
+    run(
+        runtime.execute_command(
+            "text-tools.uppercase-selection",
+            {},
+            PluginCommandContext(
+                vault_id="default", note_id="note_private", selection="visible"
+            ),
+        )
+    )
+
+    assert host.context == {"selection": "visible"}
+
+
+def test_command_resolves_only_declared_plugin_secrets(tmp_path: Path) -> None:
+    class SecretHost(DeclarativePluginHost):
+        def __init__(self) -> None:
+            self.secret = None
+            self.denied_code = None
+
+        async def execute_command(
+            self, handler, arguments, context, settings, resolve_secret
+        ):
+            self.secret = resolve_secret("api_key")
+            try:
+                resolve_secret("undeclared")
+            except ExtensionError as exc:
+                self.denied_code = exc.code
+            return PluginNoEffect()
+
+    host = SecretHost()
+    runtime = PluginRuntime(ToolRegistry(), host=host)
+    package = tmp_path / "secret-command"
+    package.mkdir()
+    (package / "plugin.yaml").write_text(
+        """
+id: secret-command
+name: Secret Command
+version: 1.0.0
+permissions: [secrets.use]
+contributes:
+  commands: [secret-command.run]
+  settings_sections: [secret-command.general]
+backend:
+  type: internal_rpc
+  transport: none
+""".strip(),
+        encoding="utf-8",
+    )
+    (package / "commands.yaml").write_text(
+        """
+commands:
+  - command_id: secret-command.run
+    title: Secret Command
+    locations: [command_palette]
+    secrets: [api_key]
+    handler: echo
+""".strip(),
+        encoding="utf-8",
+    )
+    (package / "settings.yaml").write_text(
+        """
+section_id: secret-command.general
+schema_version: 1
+fields:
+  - key: api_key
+    label: API Key
+    type: secret
+""".strip(),
+        encoding="utf-8",
+    )
+    runtime.install(package)
+    runtime.set_permissions("secret-command", ["secrets.use"])
+    runtime.enable("secret-command")
+    runtime.put_setting_secret("secret-command", "api_key", "runtime-only-secret")
+
+    run(
+        runtime.execute_command(
+            "secret-command.run",
+            {},
+            PluginCommandContext(selection="visible"),
+        )
+    )
+
+    assert host.secret == "runtime-only-secret"
+    assert host.denied_code == "PLUGIN_SECRET_ACCESS_DENIED"
+    assert "runtime-only-secret" not in repr(runtime.commands.audit_events())
+
+
+def test_settings_schema_contains_defaults_and_hides_secret() -> None:
+    container = build_container()
+
+    schema = container.plugins.get_settings("text-tools")
+    by_key = {field.key: field for field in schema.fields}
+
+    assert schema.schema_version == 1
+    assert schema.values == {
+        "result_limit": 100,
+        "label_prefix": "",
+        "output_style": "notification",
+        "enabled_hint": True,
+    }
+    assert "api_key" not in schema.values
+    assert schema.secrets["api_key"].configured is False
+    assert by_key["api_key"].type == PluginSettingType.secret
+
+
+def test_settings_update_validates_version_type_bounds_and_secret_boundary() -> None:
+    container = build_container()
+
+    updated = container.plugins.update_settings(
+        "text-tools", 1, {"result_limit": 20, "output_style": "compact"}
+    )
+    assert updated.values["result_limit"] == 20
+    assert updated.values["output_style"] == "compact"
+
+    cases = [
+        (2, {}, "PLUGIN_SETTINGS_VERSION_CONFLICT"),
+        (1, {"result_limit": 0}, "PLUGIN_SETTINGS_FIELD_INVALID"),
+        (1, {"enabled_hint": "yes"}, "PLUGIN_SETTINGS_FIELD_INVALID"),
+        (1, {"output_style": "unknown"}, "PLUGIN_SETTINGS_FIELD_INVALID"),
+        (1, {"api_key": "plaintext"}, "PLUGIN_SETTINGS_FIELD_INVALID"),
+        (1, {"unknown": True}, "PLUGIN_SETTINGS_FIELD_INVALID"),
+    ]
+    for version, values, code in cases:
+        with pytest.raises(ExtensionError) as exc:
+            container.plugins.update_settings("text-tools", version, values)
+        assert exc.value.code == code
+
+
+def test_required_plain_setting_blocks_enable_until_configured(tmp_path: Path) -> None:
+    package = tmp_path / "required-setting"
+    package.mkdir()
+    (package / "plugin.yaml").write_text(
+        """
+id: required-setting
+name: Required Setting
+version: 1.0.0
+contributes:
+  commands: [required-setting.run]
+  settings_sections: [required-setting.general]
+backend:
+  type: internal_rpc
+  transport: none
+""".strip(),
+        encoding="utf-8",
+    )
+    (package / "commands.yaml").write_text(
+        """
+commands:
+  - command_id: required-setting.run
+    title: Required Setting
+    locations: [command_palette]
+    handler: echo
+""".strip(),
+        encoding="utf-8",
+    )
+    (package / "settings.yaml").write_text(
+        """
+section_id: required-setting.general
+schema_version: 1
+fields:
+  - key: endpoint
+    label: Endpoint
+    type: string
+    required: true
+""".strip(),
+        encoding="utf-8",
+    )
+    runtime = PluginRuntime(ToolRegistry())
+    runtime.install(package)
+
+    with pytest.raises(ExtensionError) as exc:
+        runtime.enable("required-setting")
+    assert exc.value.code == "PLUGIN_SETTINGS_REQUIRED"
+    assert runtime.get("required-setting").status == "installed"
+
+    runtime.update_settings("required-setting", 1, {"endpoint": "local"})
+    assert runtime.enable("required-setting").status == "ready"
+
+
+def test_secret_roundtrip_never_enters_plain_settings_storage() -> None:
+    container = build_container()
+    plaintext = "stage-d-secret-value"
+
+    status = container.plugins.put_setting_secret("text-tools", "api_key", plaintext)
+    schema = container.plugins.get_settings("text-tools")
+    settings_path = get_settings().data_dir / "plugins" / "settings.json"
+    credentials_path = get_settings().data_dir / "credentials" / "credentials.json"
+
+    assert status.configured is True
+    assert schema.secrets["api_key"].configured is True
+    assert "api_key" not in schema.values
+    assert plaintext not in settings_path.read_text(encoding="utf-8")
+    assert plaintext not in credentials_path.read_text(encoding="utf-8")
+    stored_settings = json.loads(settings_path.read_text(encoding="utf-8"))
+    reference = stored_settings["text-tools"]["secret_refs"]["api_key"]
+    assert reference.startswith("plugin.")
+    assert len(reference) == 71
+    assert "text-tools" not in reference and "api_key" not in reference
+    assert container.credentials.resolve(reference) == plaintext
+
+    deleted = container.plugins.delete_setting_secret("text-tools", "api_key")
+    assert deleted.configured is False
+    assert container.credentials.resolve(reference) is None
+
+
+def test_uninstall_removes_plugin_settings_and_secret_namespace() -> None:
+    container = build_container()
+    container.plugins.update_settings("text-tools", 1, {"result_limit": 12})
+    container.plugins.put_setting_secret("text-tools", "api_key", "temporary")
+    settings_path = get_settings().data_dir / "plugins" / "settings.json"
+    reference = json.loads(settings_path.read_text(encoding="utf-8"))[
+        "text-tools"
+    ]["secret_refs"]["api_key"]
+
+    container.plugins.uninstall("text-tools")
+
+    stored = json.loads(settings_path.read_text(encoding="utf-8"))
+    assert "text-tools" not in stored
+    assert container.credentials.resolve(reference) is None
+
+
+def test_plugin_secret_reference_has_fixed_credential_safe_length() -> None:
+    reference = _secret_reference("p" * 512, "k" * 128)
+
+    assert reference.startswith("plugin.")
+    assert len(reference) <= 128
+
+
+def test_tampered_secret_reference_cannot_cross_credential_namespace() -> None:
+    container = build_container()
+    container.credentials.put("openai", "provider-private-secret")
+    settings_path = get_settings().data_dir / "plugins" / "settings.json"
+    settings_path.parent.mkdir(parents=True, exist_ok=True)
+    settings_path.write_text(
+        json.dumps(
+            {
+                "text-tools": {
+                    "schema_version": 1,
+                    "values": {},
+                    "secret_refs": {"api_key": "openai"},
+                }
+            }
+        ),
+        encoding="utf-8",
+    )
+
+    with pytest.raises(ExtensionError) as read_error:
+        container.plugins.get_settings("text-tools")
+    with pytest.raises(ExtensionError) as uninstall_error:
+        container.plugins.uninstall("text-tools")
+
+    assert read_error.value.code == "PLUGIN_STORAGE_ERROR"
+    assert uninstall_error.value.code == "PLUGIN_STORAGE_ERROR"
+    assert container.credentials.resolve("openai") == "provider-private-secret"
+
+
+def test_secret_delete_restores_reference_when_credential_delete_fails(
+    monkeypatch,
+) -> None:
+    container = build_container()
+    container.plugins.put_setting_secret("text-tools", "api_key", "keep-me")
+    settings_path = get_settings().data_dir / "plugins" / "settings.json"
+    original = settings_path.read_text(encoding="utf-8")
+    reference = _secret_reference("text-tools", "api_key")
+
+    def fail_delete(_credential_id: str) -> bool:
+        raise CredentialStoreError("injected delete failure")
+
+    monkeypatch.setattr(container.credentials, "delete", fail_delete)
+
+    with pytest.raises(ExtensionError) as exc:
+        container.plugins.delete_setting_secret("text-tools", "api_key")
+
+    assert exc.value.code == "PLUGIN_SECRET_STORE_ERROR"
+    assert settings_path.read_text(encoding="utf-8") == original
+    assert container.credentials.resolve(reference) == "keep-me"
+
+
+def test_uninstall_restores_settings_when_atomic_secret_delete_fails(
+    monkeypatch,
+) -> None:
+    container = build_container()
+    container.plugins.update_settings("text-tools", 1, {"result_limit": 12})
+    container.plugins.put_setting_secret("text-tools", "api_key", "keep-me")
+    settings_path = get_settings().data_dir / "plugins" / "settings.json"
+    original = settings_path.read_text(encoding="utf-8")
+    reference = _secret_reference("text-tools", "api_key")
+
+    def fail_delete_many(_credential_ids: list[str]) -> set[str]:
+        raise CredentialStoreError("injected batch delete failure")
+
+    monkeypatch.setattr(container.credentials, "delete_many", fail_delete_many)
+
+    with pytest.raises(ExtensionError) as exc:
+        container.plugins.uninstall("text-tools")
+
+    assert exc.value.code == "PLUGIN_SECRET_STORE_ERROR"
+    assert settings_path.read_text(encoding="utf-8") == original
+    assert container.credentials.resolve(reference) == "keep-me"
+    assert container.plugins.get("text-tools").manifest.plugin_id == "text-tools"
+
+
+def test_invalid_command_and_settings_manifest_are_rejected(tmp_path: Path) -> None:
+    invalid_command = tmp_path / "invalid-command"
+    invalid_command.mkdir()
+    (invalid_command / "plugin.yaml").write_text(
+        """
+id: invalid-command
+name: Invalid Command
+version: 1.0.0
+contributes:
+  commands: [other.run]
+""".strip(),
+        encoding="utf-8",
+    )
+    (invalid_command / "commands.yaml").write_text(
+        """
+commands:
+  - command_id: other.run
+    title: Invalid
+    locations: [command_palette]
+    handler: echo
+""".strip(),
+        encoding="utf-8",
+    )
+
+    invalid_settings = tmp_path / "invalid-settings"
+    invalid_settings.mkdir()
+    (invalid_settings / "plugin.yaml").write_text(
+        """
+id: invalid-settings
+name: Invalid Settings
+version: 1.0.0
+contributes:
+  settings_sections: [invalid-settings.general]
+""".strip(),
+        encoding="utf-8",
+    )
+    (invalid_settings / "settings.yaml").write_text(
+        """
+section_id: invalid-settings.general
+schema_version: 1
+fields:
+  - key: token
+    label: Token
+    type: secret
+    default: leaked-default
+""".strip(),
+        encoding="utf-8",
+    )
+
+    runtime = PluginRuntime(ToolRegistry())
+    with pytest.raises(ExtensionError) as command_error:
+        runtime.install(invalid_command)
+    assert command_error.value.code == "PLUGIN_COMMAND_INVALID"
+
+    with pytest.raises(ExtensionError) as settings_error:
+        runtime.install(invalid_settings)
+    assert settings_error.value.code == "PLUGIN_SETTINGS_SCHEMA_INVALID"
+
+
+@pytest.mark.parametrize("bound", [".nan", ".inf", "-.inf"])
+def test_non_finite_setting_bounds_are_rejected(tmp_path: Path, bound: str) -> None:
+    package = tmp_path / f"invalid-bound-{bound.replace('.', 'dot').replace('-', 'neg')}"
+    package.mkdir()
+    (package / "plugin.yaml").write_text(
+        """
+id: invalid-bound
+name: Invalid Bound
+version: 1.0.0
+contributes:
+  settings_sections: [invalid-bound.general]
+backend:
+  type: none
+  transport: none
+""".strip(),
+        encoding="utf-8",
+    )
+    (package / "settings.yaml").write_text(
+        f"""
+section_id: invalid-bound.general
+schema_version: 1
+fields:
+  - key: limit
+    label: Limit
+    type: number
+    minimum: {bound}
+""".strip(),
+        encoding="utf-8",
+    )
+
+    with pytest.raises(ExtensionError) as exc:
+        PluginRuntime(ToolRegistry()).install(package)
+
+    assert exc.value.code == "PLUGIN_SETTINGS_SCHEMA_INVALID"
+    assert "must be finite" in exc.value.message
+
+
+def test_null_command_list_returns_stable_manifest_error(tmp_path: Path) -> None:
+    package = tmp_path / "null-commands"
+    package.mkdir()
+    (package / "plugin.yaml").write_text(
+        """
+id: null-commands
+name: Null Commands
+version: 1.0.0
+contributes:
+  commands: []
+backend:
+  type: internal_rpc
+  transport: none
+""".strip(),
+        encoding="utf-8",
+    )
+    (package / "commands.yaml").write_text("commands:\n", encoding="utf-8")
+
+    with pytest.raises(ExtensionError) as exc:
+        PluginRuntime(ToolRegistry()).install(package)
+
+    assert exc.value.code == "EXTENSION_MANIFEST_INVALID"
+
+
+def test_external_command_schema_reference_is_rejected(tmp_path: Path) -> None:
+    package = tmp_path / "external-ref"
+    package.mkdir()
+    (package / "plugin.yaml").write_text(
+        """
+id: external-ref
+name: External Ref
+version: 1.0.0
+contributes:
+  commands: [external-ref.run]
+backend:
+  type: internal_rpc
+  transport: none
+""".strip(),
+        encoding="utf-8",
+    )
+    (package / "commands.yaml").write_text(
+        """
+commands:
+  - command_id: external-ref.run
+    title: External Ref
+    locations: [command_palette]
+    handler: echo
+    parameters:
+      $ref: file:///host/private-schema.json
+""".strip(),
+        encoding="utf-8",
+    )
+
+    with pytest.raises(ExtensionError) as exc:
+        PluginRuntime(ToolRegistry()).install(package)
+
+    assert exc.value.code == "PLUGIN_COMMAND_INVALID"
+    assert "External JSON Schema reference" in exc.value.message
+
+
+def test_settings_missing_and_secret_field_errors_are_stable() -> None:
+    container = build_container()
+
+    with pytest.raises(ExtensionError) as missing:
+        container.plugins.get_settings("does-not-exist")
+    assert missing.value.code == "PLUGIN_NOT_FOUND"
+
+    with pytest.raises(ExtensionError) as field:
+        container.plugins.put_setting_secret("text-tools", "result_limit", "secret")
+    assert field.value.code == "PLUGIN_SECRET_FIELD_NOT_FOUND"
+
+    with pytest.raises(ExtensionError) as empty:
+        container.plugins.put_setting_secret("text-tools", "api_key", "")
+    assert empty.value.code == "PLUGIN_SECRET_VALUE_INVALID"
+
+
+def test_corrupted_plugin_settings_namespace_returns_stable_error() -> None:
+    container = build_container()
+    settings_path = get_settings().data_dir / "plugins" / "settings.json"
+    settings_path.parent.mkdir(parents=True, exist_ok=True)
+    settings_path.write_text('{"text-tools": []}', encoding="utf-8")
+
+    with pytest.raises(ExtensionError) as exc:
+        container.plugins.get_settings("text-tools")
+
+    assert exc.value.code == "PLUGIN_STORAGE_ERROR"
+
+    with pytest.raises(ExtensionError) as secret_exc:
+        container.plugins.put_setting_secret("text-tools", "api_key", "must-not-orphan")
+
+    assert secret_exc.value.code == "PLUGIN_STORAGE_ERROR"
+    credentials_path = get_settings().data_dir / "credentials" / "credentials.json"
+    credential_ids = (
+        json.loads(credentials_path.read_text(encoding="utf-8")).keys()
+        if credentials_path.exists()
+        else []
+    )
+    assert not any(item.startswith("plugin.") for item in credential_ids)

backend/tests/test_schema_security.py

@@ -0,0 +1,65 @@
+import pytest
+
+from app.schema_security import (
+    ExternalSchemaReferenceError,
+    UnresolvableLocalSchemaReferenceError,
+    reject_external_schema_references,
+)
+
+
+@pytest.mark.parametrize(
+    "schema",
+    [
+        {"$ref": "file:///host/private-schema.json"},
+        {"properties": {"value": {"$ref": "https://schema.invalid/value.json"}}},
+        {"allOf": [{"$dynamicRef": "https://schema.invalid/dynamic"}]},
+    ],
+)
+def test_external_json_schema_references_are_rejected(schema) -> None:
+    with pytest.raises(ExternalSchemaReferenceError):
+        reject_external_schema_references(schema)
+
+
+def test_local_json_schema_fragment_reference_is_allowed() -> None:
+    reject_external_schema_references(
+        {
+            "$defs": {"value": {"type": "string"}},
+            "properties": {"value": {"$ref": "#/$defs/value"}},
+        }
+    )
+
+
+@pytest.mark.parametrize("reference", ["#/$defs/missing", "#missing-anchor"])
+def test_unresolvable_local_schema_reference_is_rejected(reference: str) -> None:
+    with pytest.raises(UnresolvableLocalSchemaReferenceError):
+        reject_external_schema_references({"type": "object", "$ref": reference})
+
+
+def test_root_reference_cannot_use_anchor_from_nested_schema_resource() -> None:
+    schema = {
+        "$defs": {
+            "nested": {
+                "$id": "nested",
+                "$anchor": "inside",
+                "type": "string",
+            }
+        },
+        "properties": {"value": {"$ref": "#inside"}},
+    }
+
+    with pytest.raises(UnresolvableLocalSchemaReferenceError):
+        reject_external_schema_references(schema)
+
+
+def test_nested_schema_resource_can_resolve_its_own_anchor() -> None:
+    schema = {
+        "$defs": {
+            "nested": {
+                "$id": "nested",
+                "$anchor": "inside",
+                "allOf": [{"$ref": "#inside"}],
+            }
+        }
+    }
+
+    reject_external_schema_references(schema)