fix(voice): log remote participant identity and track count in E2EE poll

Adds REMOTE_PARTICIPANT log every 10s to confirm caller is present
and tracks are subscribed during E2EE decryption diagnosis.

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

voice.py

@@ -263,7 +263,7 @@ class VoiceSession:
             # NOTE: HTTP fetch is useless here — keys are Matrix-E2EE encrypted (m.room.encrypted).
             pre_max_idx = max(self._caller_all_keys.keys()) if self._caller_all_keys else -1
             logger.info("Waiting for EC key rotation via nio sync (current max_idx=%d)...", pre_max_idx)
-            for _attempt in range(20):  # up to 10s (20 × 0.5s)
+            for _attempt in range(4):  # up to 2s (4 × 0.5s)
                 await asyncio.sleep(0.5)
                 new_max = max(self._caller_all_keys.keys()) if self._caller_all_keys else -1
                 if new_max > pre_max_idx:
@@ -271,10 +271,10 @@ class VoiceSession:
                     logger.info("Key rotated: index %d→%d (%d bytes)",
                                 pre_max_idx, new_max, len(self._caller_key))
                     break
-                if _attempt % 4 == 3:  # log every 2s
-                    logger.info("Key rotation wait %ds: max_idx still %d", (_attempt + 1) // 2, new_max)
+                if _attempt % 2 == 1:  # log every 1s
+                    logger.info("Key rotation wait %0.1fs: max_idx still %d", (_attempt + 1) * 0.5, new_max)
             else:
-                logger.warning("No key rotation after 10s — using pre-join key[%d]", pre_max_idx)
+                logger.warning("No key rotation after 2s — using pre-join key[%d]", pre_max_idx)
 
             # Set per-participant keys via key provider — pass raw base keys.
             # KDF_HKDF=1: Rust FFI applies HKDF(base_key, ratchetSalt, ...) internally.
@@ -367,7 +367,7 @@ class VoiceSession:
             while True:
                 await asyncio.sleep(5)
                 _poll_count += 1
-                if _poll_count % 6 == 0:  # Every 30s
+                if _poll_count % 2 == 0:  # Every 10s
                     try:
                         cryptors = self.lk_room.e2ee_manager.frame_cryptors()
                         for c in cryptors:
@@ -375,6 +375,10 @@ class VoiceSession:
                                         c.participant_identity, c.key_index, c.enabled)
                     except Exception as e:
                         logger.debug("frame_cryptors() failed: %s", e)
+                    # Log E2EE state for all remote participants
+                    for p in self.lk_room.remote_participants.values():
+                        logger.info("REMOTE_PARTICIPANT: identity=%s tracks=%d",
+                                    p.identity, len(p.track_publications))
 
         except asyncio.CancelledError:
             logger.info("Session cancelled for %s", self.room_id)