fix: wrap announce handlers in _AnnounceHandler objects

RNS.Transport.register_announce_handler silently ignores raw callables —
it only accepts objects with both `aspect_filter` attribute and
`received_announce` method.  Both bridge and gossip were registering
bound methods directly, so no announces ever fired.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/radicle_reticulum/bridge.py

@@ -87,6 +87,17 @@ class TunnelConnection:
                 pass
 
 
+class _AnnounceHandler:
+    """Wraps a callback into the object interface RNS.Transport requires."""
+    aspect_filter = f"{APP_NAME}.{ASPECT_BRIDGE}"
+
+    def __init__(self, callback):
+        self._callback = callback
+
+    def received_announce(self, destination_hash, announced_identity, app_data):
+        self._callback(destination_hash, announced_identity, app_data)
+
+
 class RadicleBridge:
     """Bridges Radicle TCP connections over Reticulum.
 
@@ -188,7 +199,7 @@ class RadicleBridge:
         self._running = True
 
         # Register announce handler to discover other bridges
-        RNS.Transport.register_announce_handler(self._handle_announce)
+        RNS.Transport.register_announce_handler(_AnnounceHandler(self._handle_announce))
         RNS.log("Registered announce handler for bridge discovery", RNS.LOG_INFO)
 
         # Load persisted NIDs first so radicle-node is ready for reconnects

src/radicle_reticulum/gossip.py

@@ -37,6 +37,17 @@ PATH_REQUEST_TIMEOUT = 15   # seconds to wait for a path before giving up
 WATCHDOG_DEBOUNCE = 2.0     # seconds to absorb rapid filesystem events before polling
 
 
+class _AnnounceHandler:
+    """Wraps a callback into the object interface RNS.Transport requires."""
+    aspect_filter = f"{APP_NAME}.{ASPECT_GOSSIP}"
+
+    def __init__(self, callback):
+        self._callback = callback
+
+    def received_announce(self, destination_hash, announced_identity, app_data):
+        self._callback(destination_hash, announced_identity, app_data)
+
+
 def _radicle_storage_path() -> Path:
     """Return ~/.radicle/storage, using 'rad path' if available."""
     try:
@@ -155,7 +166,7 @@ class GossipRelay:
     def start(self):
         """Start the relay: announce, begin polling, register announce handler."""
         self._running = True
-        RNS.Transport.register_announce_handler(self._on_announce)
+        RNS.Transport.register_announce_handler(_AnnounceHandler(self._on_announce))
         self.announce()
         threading.Thread(target=self._startup_announce_loop, daemon=True).start()
         self._start_watcher()