feat(channels): add QQ Official channel via Tencent Bot SDK

Implement QQ Official messaging channel using OAuth2 authentication
with Discord-like WebSocket gateway protocol for events.

- Add QQChannel with send/listen/health_check support
- Add QQConfig (app_id, app_secret, allowed_users)
- OAuth2 token refresh and WebSocket heartbeat management
- Message deduplication with capacity-based eviction
- Support both C2C (private) and group AT messages
- Integrate with onboard wizard, integrations registry, and channel
  list/doctor commands
- Include unit tests for user allowlist, deduplication, and config

src/config/schema.rs

@@ -1283,6 +1283,7 @@ pub struct ChannelsConfig {
     pub irc: Option<IrcConfig>,
     pub lark: Option<LarkConfig>,
     pub dingtalk: Option<DingTalkConfig>,
+    pub qq: Option<QQConfig>,
 }
 
 impl Default for ChannelsConfig {
@@ -1301,6 +1302,7 @@ impl Default for ChannelsConfig {
             irc: None,
             lark: None,
             dingtalk: None,
+            qq: None,
         }
     }
 }
@@ -1632,6 +1634,18 @@ pub struct DingTalkConfig {
     pub allowed_users: Vec<String>,
 }
 
+/// QQ Official Bot configuration (Tencent QQ Bot SDK)
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct QQConfig {
+    /// App ID from QQ Bot developer console
+    pub app_id: String,
+    /// App Secret from QQ Bot developer console
+    pub app_secret: String,
+    /// Allowed user IDs. Empty = deny all, "*" = allow all
+    #[serde(default)]
+    pub allowed_users: Vec<String>,
+}
+
 // ── Config impl ──────────────────────────────────────────────────
 
 impl Default for Config {
@@ -2173,6 +2187,7 @@ default_temperature = 0.7
                 irc: None,
                 lark: None,
                 dingtalk: None,
+                qq: None,
             },
             memory: MemoryConfig::default(),
             tunnel: TunnelConfig::default(),
@@ -2587,6 +2602,7 @@ tool_dispatcher = "xml"
             irc: None,
             lark: None,
             dingtalk: None,
+            qq: None,
         };
         let toml_str = toml::to_string_pretty(&c).unwrap();
         let parsed: ChannelsConfig = toml::from_str(&toml_str).unwrap();
@@ -2748,6 +2764,7 @@ channel_id = "C123"
             irc: None,
             lark: None,
             dingtalk: None,
+            qq: None,
         };
         let toml_str = toml::to_string_pretty(&c).unwrap();
         let parsed: ChannelsConfig = toml::from_str(&toml_str).unwrap();