fix(qconnect): announce the persisted device name from every identity path

With a custom name set, the controller bootstrap announced it but the
deferred renderer join and resolve_local_identity used the DEFAULT name —
one device_uuid, two friendly names. When the server's ADD_RENDERER omits
the uuid (observed on the wire), the name-fingerprint self-match failed,
local_renderer_id stayed None and the is_local_renderer_active gate
dropped every renderer report (mute renderer, frozen controller seekbar).
default_qconnect_device_info() now resolves the persisted name on both
frontends, so all announce paths agree by construction. Wire-verified:
ADD_RENDERER carries the custom name and reports flow.

km

crates/qbzd/src/qconnect/transport.rs

@@ -266,9 +266,22 @@ pub fn build_set_position_player_state_request(
     }
 }
 
-/// Build the device-info payload with the default friendly name.
+/// Load the persisted custom device name from the daemon-root settings DB.
+/// Fail-open: None when `init_settings_db_path` never ran or on any read error.
+fn load_persisted_device_name() -> Option<String> {
+    qconnect_settings_db_path().and_then(|path| load_device_name_at(&path))
+}
+
+/// Build the device-info payload with the EFFECTIVE friendly name: the persisted
+/// custom device name when one is set, else the default. The persisted name must
+/// win here (not only at the controller-bootstrap call site that threads it
+/// explicitly): with a custom name set, announcing the DEFAULT name from the
+/// renderer join / local identity gives ONE device_uuid TWO friendly names, and
+/// when the server's ADD_RENDERER omits the uuid the name-fingerprint self-match
+/// fails -> `local_renderer_id = None` -> every renderer report is dropped by the
+/// `is_local_renderer_active` gate (mute renderer, frozen controller seekbar).
 pub fn default_qconnect_device_info() -> QconnectDeviceInfoPayload {
-    default_qconnect_device_info_with_name(None)
+    default_qconnect_device_info_with_name(load_persisted_device_name().as_deref())
 }
 
 /// Build the device-info payload, overriding the friendly name when a custom