refactor: simplify mqtt pipeline state and remove event table

backend/app/mqtt/parsers/mixed.py

@@ -3,7 +3,27 @@ from __future__ import annotations
 from typing import Any
 
 from app.mqtt.parsers.nmea import parse_nmea_sentences
-from app.mqtt.parsers.rtcm import summarize_rtcm_types
+
+
+def summarize_rtcm_types(payload: bytes) -> dict[int, int]:
+    counts: dict[int, int] = {}
+    i = 0
+
+    while i + 6 <= len(payload):
+        if payload[i] != 0xD3:
+            i += 1
+            continue
+
+        length = ((payload[i + 1] & 0x03) << 8) | payload[i + 2]
+        frame_end = i + 3 + length + 3
+        if frame_end > len(payload):
+            break
+
+        message_type = ((payload[i + 3] << 4) | (payload[i + 4] >> 4)) & 0x0FFF
+        counts[message_type] = counts.get(message_type, 0) + 1
+        i = frame_end
+
+    return counts
 
 
 def parse_mixed_payload(payload: bytes) -> list[dict[str, Any]]: