feat: add edit_message + streaming support to Zulip adapter

Implements edit_message() using Zulip's PATCH /api/v1/messages/{id} API.
Enables the Hermes GatewayStreamConsumer to progressively update Zulip
messages during agent generation, giving users real-time visibility into
agent thinking via progressive edits.

Adds _api_patch() helper for PATCH HTTP method.

hermes-zulip-plugin/src/adapter.py

@@ -203,6 +203,22 @@ class ZulipAdapter(BasePlatformAdapter):
             logger.error("Zulip POST %s network error: %s", path, exc)
             return {"result": "error", "msg": str(exc)}
 
+    async def _api_patch(self, path: str, payload: Dict[str, Any]) -> Dict[str, Any]:
+        import aiohttp
+        url = f"{self._site}/api/v1/{path.lstrip('/')}"
+        try:
+            async with self._session.patch(
+                url, data=payload, auth=self._auth(),
+                timeout=aiohttp.ClientTimeout(total=15),
+            ) as resp:
+                data = await resp.json()
+                if resp.status >= 400:
+                    logger.debug("Zulip PATCH %s -> %s: %s", path, resp.status, str(data)[:200])
+                return data
+        except (aiohttp.ClientError, asyncio.TimeoutError) as exc:
+            logger.debug("Zulip PATCH %s network error: %s", path, exc)
+            return {"result": "error", "msg": str(exc)}
+
     async def _api_delete(self, path: str, params: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
         import aiohttp
         url = f"{self._site}/api/v1/{path.lstrip('/')}"
@@ -326,6 +342,23 @@ class ZulipAdapter(BasePlatformAdapter):
 
         return SendResult(success=True, message_id=str(last_id) if last_id else None)
 
+    async def edit_message(
+        self,
+        chat_id: str,
+        message_id: str,
+        content: str,
+        **kwargs,
+    ) -> SendResult:
+        """Edit a previously-sent message. Used by the gateway stream consumer
+        for progressive message updates during agent streaming."""
+        formatted = self.format_message(content)
+        data = await self._api_patch(f"messages/{message_id}", {"content": formatted})
+        if data.get("result") != "success":
+            msg = str(data.get("msg", "edit failed"))
+            logger.debug("Zulip edit_message(%s) -> %s", message_id, msg)
+            return SendResult(success=False, error=msg)
+        return SendResult(success=True, message_id=message_id)
+
     async def get_chat_info(self, chat_id: str) -> Dict[str, Any]:
         kind, to, topic = _parse_target(chat_id, self._default_topic)
         if kind == "direct":