feat(chat): ChatService facade — unified chat CRUD + LLM generation (#645)

CLAUDE.md

@@ -146,7 +146,7 @@ Always run lint locally before pushing. Protected branches require PR workflow 
 
 ### Modular Infrastructure (`modules/`)
 
-Foundation layer for modular decomposition (issue #489). Phase 4 complete: all 28 routers migrated (Phase 3), all inline endpoints extracted (Phase 4.1–4.5), all background tasks via `TaskRegistry` (Phase 4.6), all startup helpers + service init extracted to domain `startup.py` modules, global service variables removed (Phase 4.7a/b). Phase 5.1–5.4 complete (EventBus infrastructure, first events, DatasetSynced, Widget→CRM events). Phase 6 complete (Protocol interfaces for AuthService, KnowledgeService, LLMService, ChatService in `modules/*/protocols.py`). Phase 7.1 complete (AuthService facade in `modules/core/auth_service.py`). Phase 7.2 complete (KnowledgeService facade in `modules/knowledge/facade.py`). Phase 7.3 complete (LLMService facade in `modules/llm/facade.py`). Phase 7.4 pending.
+Foundation layer for modular decomposition (issue #489). Phase 4 complete: all 28 routers migrated (Phase 3), all inline endpoints extracted (Phase 4.1–4.5), all background tasks via `TaskRegistry` (Phase 4.6), all startup helpers + service init extracted to domain `startup.py` modules, global service variables removed (Phase 4.7a/b). Phase 5.1–5.4 complete (EventBus infrastructure, first events, DatasetSynced, Widget→CRM events). Phase 6 complete (Protocol interfaces for AuthService, KnowledgeService, LLMService, ChatService in `modules/*/protocols.py`). Phase 7.1 complete (AuthService facade in `modules/core/auth_service.py`). Phase 7.2 complete (KnowledgeService facade in `modules/knowledge/facade.py`). Phase 7.3 complete (LLMService facade in `modules/llm/facade.py`). Phase 7.4 complete (ChatService facade in `modules/chat/facade.py`).
 
 - **`EventBus`** (`modules/core/events.py`): In-process async pub/sub. Handlers run concurrently via `asyncio.gather`; exceptions are logged, never propagated to publisher. `BaseEvent` dataclass with auto-timestamp. Singleton in `ServiceContainer.event_bus`. Domain events: `InternetStatusChanged`, `UserRoleChanged`, `SessionRevoked`, `DatasetSynced` (in `modules/core/events.py`), `KnowledgeUpdated` (in `modules/knowledge/events.py`), `WidgetSessionCreated`, `WidgetMessageSent`, `WidgetContactSubmitted` (in `modules/channels/widget/events.py`). Subscriptions registered via `setup_event_subscriptions()` in `modules/core/startup.py`, which delegates to domain-specific setup functions (`setup_llm_event_subscriptions()` in `modules/llm/startup.py`, `setup_knowledge_event_subscriptions()` in `modules/knowledge/startup.py`, `setup_crm_event_subscriptions()` in `modules/crm/startup.py`). `DatasetSynced` decouples CRM/ecommerce/kanban from knowledge. Widget events decouple widget router from amoCRM: widget publishes events, CRM domain handles lead/contact/note creation reactively.
 - **`TaskRegistry`** (`modules/core/tasks.py`): Named background tasks — periodic (interval-based) or one-shot. `start_all()` / `cancel_all(timeout)` lifecycle. `TaskInfo` dataclass tracks status, run count, last error. 6 tasks registered in `startup_event()`: `session-cleanup` (1h), `periodic-vacuum` (7d), `kanban-sync` (15min), `woocommerce-sync` (daily 23:00 UTC), `wiki-embeddings` (one-shot), `wiki-collection-indexes` (one-shot). Task functions in `modules/core/maintenance.py`, `modules/knowledge/tasks.py`, `modules/kanban/tasks.py`, `modules/ecommerce/tasks.py`.
@@ -166,6 +166,7 @@ Import from `modules.core`: `EventBus`, `BaseEvent`, `TaskRegistry`, `TaskInfo`,
 | `modules/core/` | `auth_service.py` | `AuthService` (Phase 7.1 facade — wraps `auth_manager.py` functions, implements Protocol from `protocols.py`) |
 | `modules/knowledge/` | `facade.py` | `KnowledgeServiceImpl` (Phase 7.2 facade — wraps `wiki_rag_service` + knowledge services, implements Protocol from `protocols.py`) |
 | `modules/llm/` | `facade.py` | `LLMServiceImpl` (Phase 7.3 facade — wraps `CloudLLMService`/`VLLMLLMService` + `CloudProviderService`, implements Protocol from `protocols.py`) |
+| `modules/chat/` | `facade.py` | `ChatServiceImpl` (Phase 7.4 facade — wraps `ChatService` CRUD + LLM generation + `ChatShareService`, implements Protocol from `protocols.py`) |
 | `modules/chat/` | `service.py` | `ChatService`, `ChatShareService` |
 | `modules/knowledge/` | `service.py` | `FAQService`, `KnowledgeDocService`, `KnowledgeCollectionService`, `GitHubRepoProjectService` |
 | `modules/channels/telegram/` | `service.py` | `BotInstanceService`, `TelegramSessionService` |

app/dependencies.py

@@ -45,6 +45,9 @@ def __init__(self):
         # LLM service facade (Phase 7.3)
         self.llm_service_facade = None
 
+        # Chat service facade (Phase 7.4)
+        self.chat_service_facade = None
+
         # STT service
         self.stt_service: STTService | None = None