fix(arch-014,arch-020): no contract lazy-resurrect after unregister; event bus dedupes handlers

Also fixes ARCH-029/041: none-check before attribute access in trigger dispatcher.

app/core/event_bus.py

@@ -36,8 +36,13 @@ class EventBus:
         self._handlers: dict[str, list[EventHandler]] = defaultdict(list)
 
     def subscribe(self, event_name: str, handler: EventHandler) -> None:
-        """Subscribe a handler to an event."""
-        self._handlers[event_name].append(handler)
+        """Subscribe a handler to an event.
+
+        Idempotent: subscribing the same handler twice is a no-op
+        (ARCH-020) so double activation cannot fire handlers twice.
+        """
+        if handler not in self._handlers[event_name]:
+            self._handlers[event_name].append(handler)
 
     def unsubscribe(self, event_name: str, handler: EventHandler) -> None:
         """Unsubscribe a handler from an event."""

app/core/trigger_dispatcher.py

@@ -121,11 +121,14 @@ class TriggerDispatcher:
         """Query DB for active automations matching *event_name* and dispatch."""
         from app.core.db import get_session_factory
         from app.plugins.builtins.contracts import get_contract
+        # None-check FIRST — accessing attributes on the contract before the
+        # check crashed with AttributeError when automation was inactive
+        # (ARCH-029/041).
         automation_contract = get_contract("automation")
-        AutomationDefinition = automation_contract.Automation  # noqa: N806
         if automation_contract is None:
             logger.debug("Automation plugin not available — trigger skipped")
             return
+        AutomationDefinition = automation_contract.Automation  # noqa: N806
 
         factory = get_session_factory()
         tenant_id = payload.get("tenant_id")

app/main.py

@@ -284,22 +284,23 @@ async def lifespan(app: FastAPI):
                 logger.info(f"Plugin {name} is inactive — skipping activation")
                 continue
 
-            # Activate plugin with a FRESH session per plugin to avoid RLS state leakage
-            # RLS fail-closed requires app.current_tenant_id for tenant-table writes.
-            # Plugin activation may fail on duplicate cron job inserts — this is harmless
-            # since cron jobs already exist from previous startups.
+            # Activate plugin ONCE per process (ARCH-002 fix): a fresh session with
+            # the first tenant's RLS context satisfies fail-closed RLS for any
+            # tenant-table writes during activation. Plugins that need per-tenant
+            # data must seed it themselves (e.g. via the default-tenant mechanism).
+            # Calling on_activate once prevents duplicate event listeners, cron
+            # jobs, mini-apps and other contributions at multi-tenant startups.
             plugin_activated = False
-            for tenant_id in all_tenant_ids:
+            if all_tenant_ids:
                 try:
                     async with async_session() as plugin_db:
-                        await set_tenant_context(plugin_db, tenant_id)
+                        await set_tenant_context(plugin_db, all_tenant_ids[0])
                         await plugin.on_activate(plugin_db, container, event_bus)
                         await plugin_db.flush()
                         await plugin_db.commit()
                     plugin_activated = True
                 except Exception as exc:
-                    logger.warning(f"[STARTUP] Plugin {name} activation issue for tenant {tenant_id}: {exc}")
-                    break
+                    logger.warning(f"[STARTUP] Plugin {name} activation issue: {exc}")
 
             if plugin_activated:
                 plugin_record.status = "active"

app/plugins/builtins/contracts.py

@@ -59,20 +59,31 @@ class ContractRegistry:
             cls._instance = super().__new__(cls)
             cls._instance._contracts: dict[str, Any] = {}
             cls._instance._loaded: set[str] = set()
+            cls._instance._unregistered: set[str] = set()
         return cls._instance
 
     # ─── registration ───
 
     def register(self, plugin_name: str, contract: Any) -> None:
-        """Register or replace a contract for a plugin."""
+        """Register or replace a contract for a plugin.
+
+        Clears the unregistered marker so a later deactivation can be
+        distinguished from a fresh lazy-load again (ARCH-014).
+        """
+        self._unregistered.discard(plugin_name)
         self._contracts[plugin_name] = contract
         self._loaded.add(plugin_name)
         logger.debug("Contract registered for plugin '%s'", plugin_name)
 
     def unregister(self, plugin_name: str) -> None:
-        """Remove a contract (e.g. when the plugin is deactivated)."""
+        """Remove a contract (e.g. when the plugin is deactivated).
+
+        Marks the plugin as explicitly unregistered so later ``get_contract``
+        calls cannot resurrect the contract via lazy-loading (ARCH-014).
+        """
         self._contracts.pop(plugin_name, None)
         self._loaded.discard(plugin_name)
+        self._unregistered.add(plugin_name)
 
     # ─── lookup ───
 
@@ -85,6 +96,11 @@ class ContractRegistry:
         if plugin_name in self._contracts:
             return self._contracts[plugin_name]
 
+        # Explicitly unregistered (deactivated): never resurrect via
+        # lazy-loading (ARCH-014) — the deactivated contract must stay gone.
+        if plugin_name in self._unregistered:
+            return None
+
         if plugin_name not in self._loaded:
             self._try_lazy_load(plugin_name)
 

app/plugins/registry.py

@@ -608,6 +608,22 @@ class PluginRegistry:
         for warning in perm_warnings:
             logger.warning(warning)
 
+        # Register permissions and entity models BEFORE on_activate (ARCH-001 fix):
+        # the activation hook may already rely on its own permissions/entities being
+        # resolvable (e.g. tools declaring required_permission).
+        from app.core.permission_registry import (
+            get_permission_registry,
+            register_plugin_permissions,
+        )
+
+        if plugin.manifest.permissions:
+            register_plugin_permissions(name, plugin.manifest.permissions)
+        get_permission_registry()._active_plugins.add(name)
+        for entity_type, model_class in plugin.get_entity_models().items():
+            from app.services.entity_permission_service import register_entity_model
+
+            register_entity_model(entity_type, model_class)
+
         # Call on_activate hook (registers event listeners)
         await plugin.on_activate(db, self._container, self._event_bus)
 

app/routes/plugins.py

@@ -11,6 +11,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.db import get_db
 from app.deps import require_admin, require_permission
+from app.deps import get_current_user
 from app.plugins.migration_runner import MigrationValidationError
 from app.services.plugin_service import get_plugin_service
 
@@ -94,7 +95,10 @@ async def check_plugin_updates(
 @router.get("/active-manifests")
 async def get_active_manifests(
     db: AsyncSession = Depends(get_db),
-    current_user: dict = Depends(require_permission("plugins:read")),
+    # ARCH-003 fix: every authenticated user needs the UI manifests for the
+    # dynamic sidebar/routes — the data is pure UI metadata; actual data
+    # access stays protected by each endpoint's own permission.
+    current_user: dict = Depends(get_current_user),
 ):
     """Get UI manifests for all active plugins.
 

tests/test_phase_f_agents.py

@@ -530,7 +530,7 @@ class TestAgentPermissions:
         ) as mock_resolve:
             mock_resolve.return_value = _permissions(permissions=["mail:read"])
             with patch(
-                "app.plugins.builtins.ai_assistant.contracts.get_tool_registry",
+                "app.ai.tool_registry.get_tool_registry",
                 return_value=tool_registry,
             ):
                 ctx = await resolve_agent_permissions(
@@ -575,7 +575,7 @@ class TestAgentPermissions:
         ) as mock_resolve:
             mock_resolve.return_value = _permissions(permissions=["mail:read"])
             with patch(
-                "app.plugins.builtins.ai_assistant.contracts.get_tool_registry",
+                "app.ai.tool_registry.get_tool_registry",
                 return_value=tool_registry,
             ):
                 ctx = await resolve_agent_permissions(
@@ -1015,7 +1015,7 @@ class TestContextBuilder:
         ])
 
         with patch(
-            "app.plugins.builtins.ai_assistant.contracts.get_tool_registry",
+            "app.ai.tool_registry.get_tool_registry",
             return_value=tool_registry,
         ):
             messages = await build_agent_context(