feat(channel): add QQ channel support and image message pipeline (#199)

* feat(channel): add qq adapter and outbound delivery

* feat(channel): ingest inbound qq messages

* feat(web): expose qq channel in management ui

* feat(channel): support qq attachment ingestion

* fix(mcp): fail read raw immediately for missing files

* fix(agent): parse inline image data into native image parts

* test(agent): align read_media tool tests with SDK options

* fix(channel): harden qq image delivery and reconnect loop

Avoid data URLs for qq channel images, reset reconnect backoff after healthy sessions, and fall back gracefully for malformed public image URLs.

* fix(channel): restore qq media delivery and target resolution

* fix(qq,mcp,agent): fix message/qq regressions and pass go lint

* fix(qq,agent): validate inline base64 and sync heartbeat seq

* fix(qq): validate remote voice mime for upload checks

* fix(qq): fall back intents and restore adapter wiring

* fix(qq): prevent final text leakage and dedupe persisted inbound query

internal/attachment/normalize.go

@@ -35,6 +35,9 @@ func NormalizeMime(raw string) string {
 	if idx := strings.Index(mime, ";"); idx >= 0 {
 		mime = strings.TrimSpace(mime[:idx])
 	}
+	if !strings.Contains(mime, "/") {
+		return ""
+	}
 	return mime
 }