fix: add deleted_at columns to ai_proactive migration

- ai_proactive_suggestions: add deleted_at TIMESTAMPTZ
- ai_proactive_context_log: add deleted_at TIMESTAMPTZ
- ai_proactive_settings: add deleted_at TIMESTAMPTZ

ORM models expect deleted_at for soft-delete support.

app/plugins/builtins/ai_proactive/migrations/0001_initial.sql

@@ -16,7 +16,8 @@ CREATE TABLE IF NOT EXISTS ai_proactive_suggestions (
     is_acted_upon BOOLEAN NOT NULL DEFAULT FALSE,
     context_snapshot JSONB NOT NULL DEFAULT '{}',
     created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
-    expires_at TIMESTAMPTZ
+    expires_at TIMESTAMPTZ,
+    deleted_at TIMESTAMPTZ
 );
 CREATE INDEX IF NOT EXISTS ix_suggestions_user ON ai_proactive_suggestions (tenant_id, user_id, is_dismissed, created_at DESC);
 CREATE INDEX IF NOT EXISTS ix_suggestions_entity ON ai_proactive_suggestions (tenant_id, entity_type, entity_id);
@@ -30,7 +31,8 @@ CREATE TABLE IF NOT EXISTS ai_proactive_context_log (
     entity_type VARCHAR(50),
     entity_id UUID,
     entity_data JSONB NOT NULL DEFAULT '{}',
-    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    deleted_at TIMESTAMPTZ
 );
 CREATE INDEX IF NOT EXISTS ix_context_log_user_time ON ai_proactive_context_log (tenant_id, user_id, created_at DESC);
 
@@ -46,5 +48,6 @@ CREATE TABLE IF NOT EXISTS ai_proactive_settings (
     model VARCHAR(100) NOT NULL DEFAULT 'gpt-4o-mini',
     created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
     updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    deleted_at TIMESTAMPTZ,
     UNIQUE(tenant_id, user_id)
 );