fix: robust router send with auto-reconnect, 10ms timeout

- try_send() helper: reconnect on send failure
- 10ms socket timeout instead of 300ms (stalls poll loop)
- Refresh path also uses try_send
- Remove committed library bloat from repo (add .gitignore)

scripts/led-matrix-viz.py

@@ -47,7 +47,7 @@ def render(active_notes):
 
 def connect_router():
     router = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-    router.setblocking(False)
+    router.settimeout(0.01)
     try:
         router.connect(ROUTER_SOCK)
     except OSError:
@@ -55,6 +55,18 @@ def connect_router():
     return router
 
 
+def try_send(router, data):
+    try:
+        router.sendall(data)
+        return router, True
+    except (BlockingIOError, OSError):
+        try:
+            router.close()
+        except OSError:
+            pass
+        return connect_router(), False
+
+
 def main():
     sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
     sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
@@ -131,11 +143,11 @@ def main():
 
         # Try to send pending frame — no POLLOUT dependency
         if pending_bytes is not None:
-            try:
-                router.sendall(pending_bytes)
+            router, ok = try_send(router, pending_bytes)
+            if ok:
                 pending_bytes = None
                 frames_sent += 1
-            except (BlockingIOError, OSError):
+            else:
                 frames_dropped += 1
 
         # Background refresh: resend last params to recover from router drops
@@ -145,11 +157,9 @@ def main():
             if last_sent_params is not None and pending_bytes is None:
                 msg_id = (msg_id + 1) % 65535
                 refresh_bytes = packer.pack([0, msg_id, "draw_frame", last_sent_params])
-                try:
-                    router.sendall(refresh_bytes)
+                router, ok = try_send(router, refresh_bytes)
+                if ok:
                     frames_sent += 1
-                except (BlockingIOError, OSError):
-                    pass
 
             if now - stats_last_write >= 2.0:
                 fps = fps_sample_frames / (now - fps_sample_start) if (now - fps_sample_start) > 0 else 0