fix: QQBot missing integration points, timestamp parsing, test fix

- Add Platform.QQBOT to _UPDATE_ALLOWED_PLATFORMS (enables /update command)
- Add 'qqbot' to webhook cross-platform delivery routing
- Add 'qqbot' to hermes dump platform detection
- Fix test_name_property casing: 'QQBot' not 'QQBOT'
- Add _parse_qq_timestamp() for ISO 8601 + integer ms compatibility
  (QQ API changed timestamp format — from PR #2411 finding)
- Wire timestamp parsing into all 4 message handlers

gateway/platforms/webhook.py

@@ -203,6 +203,7 @@ class WebhookAdapter(BasePlatformAdapter):
             "wecom_callback",
             "weixin",
             "bluebubbles",
+            "qqbot",
         ):
             return await self._deliver_cross_platform(
                 deliver_type, content, delivery