feat: add QQ Bot platform adapter (Official API v2)

Add full QQ Bot integration via the Official QQ Bot API (v2):
- WebSocket gateway for inbound events (C2C, group, guild, DM)
- REST API for outbound text/markdown/media messages
- Voice transcription (Tencent ASR + configurable STT provider)
- Attachment processing (images, voice, files)
- User authorization (allowlist + allow-all + DM pairing)

Integration points:
- gateway: Platform.QQ enum, adapter factory, allowlist maps
- CLI: setup wizard, gateway config, status display, tools config
- tools: send_message cross-platform routing, toolsets
- cron: delivery platform support
- docs: QQ Bot setup guide

cli-config.yaml.example

@@ -552,6 +552,7 @@ agent:
 #   slack:         hermes-slack          (same as telegram)
 #   signal:        hermes-signal         (same as telegram)
 #   homeassistant: hermes-homeassistant  (same as telegram)
+#   qq:            hermes-qq            (same as telegram)
 #
 platform_toolsets:
   cli: [hermes-cli]
@@ -561,6 +562,7 @@ platform_toolsets:
   slack: [hermes-slack]
   signal: [hermes-signal]
   homeassistant: [hermes-homeassistant]
+  qq: [hermes-qq]
 
 # ─────────────────────────────────────────────────────────────────────────────
 # Available toolsets (use these names in platform_toolsets or the toolsets list)