fix(client): address PR #4 round 2 review feedback

- decode_snapshot() reports dropped entities via push_error and returns
  decode_errors count so callers can detect partial data (D-010
  information boundary compliance)
- receive_bytes() warns when overwriting unconsumed snapshot, documents
  latest-wins semantics
- Rename misleading test to test_encode_produces_nonempty_bytes
- Fix tick rate comment: 10 ticks/game-minute per D-031

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

client/scripts/autoloads/sim_bridge.gd

@@ -75,9 +75,13 @@ func poll_snapshot() -> Variant:
 	return null
 
 # Called by transport layer (ticket #79) when raw bytes arrive from the server.
+# Latest-wins semantics: newer snapshots replace unconsumed ones. This is correct
+# for real-time rendering (stale frames are worthless). Upgrade to queue if needed.
 func receive_bytes(bytes: PackedByteArray) -> void:
 	var snapshot = Protocol.decode_snapshot(bytes)
 	if snapshot != null:
+		if _last_snapshot != null:
+			push_warning("SimBridge: overwriting unconsumed snapshot (tick %s replaced by %s)" % [_last_snapshot.tick, snapshot.tick])
 		_last_snapshot = snapshot
 
 # Drain the outbound buffer. Called by transport layer (ticket #79) to get encoded messages.