feat(channel-service): add Python FastAPI pywechat channel service

- Add FastAPI project under channel-service/
- Implement mock pywechat client adapter (login, send, heartbeat)
- Add /v1/wechat-personal/login/*, /v1/wechat-personal/send/* APIs
- Add /v1/heartbeat and /v1/monitor/status for client health
- Add /monitor HTML page with Web Components
- Add pytest suite and Dockerfile
- Update .gitignore for Python/Node artifacts

channel-service/app/services/heartbeat_service.py

@@ -0,0 +1,32 @@
+from __future__ import annotations
+
+import time
+
+from app.clients.pywechat_client import ClientRegistry, OnlineStatus, registry
+
+
+class HeartbeatService:
+    def __init__(self, registry: ClientRegistry):
+        self.registry = registry
+
+    def heartbeat(self, account_id: str, payload: dict) -> dict:
+        client = self.registry.get_or_create(account_id, payload.get("account_name"))
+        client.heartbeat()
+        if "risk_level" in payload:
+            client.state.risk_level = payload["risk_level"]
+        if "sent_count_today" in payload:
+            client.state.sent_count_today = payload["sent_count_today"]
+        return {"success": True, "account_id": account_id}
+
+    def check_offline_accounts(self, timeout_seconds: int = 120) -> list[dict]:
+        now = time.time()
+        offline = []
+        for client in self.registry.list_all():
+            last = client.state.last_heartbeat_at
+            if client.state.online_status == OnlineStatus.ONLINE and (last is None or now - last > timeout_seconds):
+                client.state.online_status = OnlineStatus.OFFLINE
+                offline.append({"account_id": client.state.account_id, "last_heartbeat_at": last})
+        return offline
+
+
+heartbeat_service = HeartbeatService(registry)

channel-service/app/services/login_service.py

@@ -0,0 +1,53 @@
+from __future__ import annotations
+
+import time
+from typing import Optional
+
+from app.clients.pywechat_client import ClientRegistry, LoginStatus, OnlineStatus, registry
+
+
+class LoginService:
+    def __init__(self, registry: ClientRegistry):
+        self.registry = registry
+
+    def start_login(self, account_id: str, account_name: Optional[str] = None) -> dict:
+        client = self.registry.get_or_create(account_id, account_name)
+        login_id = client.start_login()
+        return {
+            "login_id": login_id,
+            "qr_code_url": client.state.qr_code_url,
+            "status": client.state.login_status.value,
+        }
+
+    def get_status(self, account_id: str) -> dict:
+        client = self.registry.get(account_id)
+        if client is None:
+            return {"found": False, "account_id": account_id}
+        state = client.get_state()
+        return {
+            "found": True,
+            "account_id": state.account_id,
+            "account_name": state.account_name,
+            "login_status": state.login_status.value,
+            "online_status": state.online_status.value,
+            "last_heartbeat_at": state.last_heartbeat_at,
+            "risk_level": state.risk_level,
+            "sent_count_today": state.sent_count_today,
+        }
+
+    def confirm_login(self, account_id: str) -> dict:
+        client = self.registry.get(account_id)
+        if client is None:
+            return {"success": False, "error": "account not found"}
+        client.confirm_login()
+        return {"success": True, "status": client.state.login_status.value}
+
+    def expire_login(self, account_id: str) -> dict:
+        client = self.registry.get(account_id)
+        if client is None:
+            return {"success": False, "error": "account not found"}
+        client.expire_login()
+        return {"success": True, "status": client.state.login_status.value}
+
+
+login_service = LoginService(registry)

channel-service/app/services/send_service.py

@@ -0,0 +1,33 @@
+from __future__ import annotations
+
+from app.clients.pywechat_client import ClientRegistry, OnlineStatus, registry
+
+
+class SendService:
+    def __init__(self, registry: ClientRegistry):
+        self.registry = registry
+
+    def send_text(self, account_id: str, conversation_id: str, text: str) -> dict:
+        client = self.registry.get(account_id)
+        if client is None:
+            return {"success": False, "error": f"account {account_id} not registered"}
+        if client.state.online_status != OnlineStatus.ONLINE:
+            return {"success": False, "error": "account not online"}
+        return client.send_text(conversation_id, text)
+
+    def send_image(self, account_id: str, conversation_id: str, image_url: str) -> dict:
+        # Placeholder for image sending via pywechat.
+        client = self.registry.get(account_id)
+        if client is None:
+            return {"success": False, "error": f"account {account_id} not registered"}
+        if client.state.online_status != OnlineStatus.ONLINE:
+            return {"success": False, "error": "account not online"}
+        return {
+            "success": True,
+            "message_id": f"mock-img-{image_url.split('/')[-1]}",
+            "conversation_id": conversation_id,
+            "type": "image",
+        }
+
+
+send_service = SendService(registry)