server: guard against None snapshots crashing the accept loop

If extract_all() returns None (Dashboard init failure), appending it to
store["records"] would cause _accept_loop to crash with AttributeError on
the next client connection.  Since only OSError was caught, the thread
died permanently — no further clients could join push_clients, so live
broadcasts reached nobody.

- collect.py: skip None snapshots instead of appending them
- network.py: filter None records in _accept_loop; catch all exceptions
  during history send (not just OSError) so the thread survives
- storage_helpers.py: filter None records when loading from disk

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

server/collect.py

@@ -49,7 +49,7 @@ def run(args: argparse.Namespace) -> None:
     push_clients, push_lock, push_store_ref = network.start_push_server(args.host, args.port)
     push_store_ref["preloaded"] = load_last_24h_records(logs_dir, vin)
     for _r in push_store_ref["preloaded"]:
-        if "procedural" not in _r:
+        if _r is not None and "procedural" not in _r:
             apply_procedural(_r)
     if push_store_ref["preloaded"]:
         log.info("Pre-loaded %d record(s) from the last 24 h", len(push_store_ref["preloaded"]))
@@ -57,7 +57,7 @@ def run(args: argparse.Namespace) -> None:
     current_day = datetime.now(timezone.utc).date()
     store = load_store(out, vin, args.interval)
     for _r in store["records"]:
-        if "procedural" not in _r:
+        if _r is not None and "procedural" not in _r:
             apply_procedural(_r)
     push_store_ref["current"] = store
     last_broadcast: dict = {}
@@ -86,6 +86,9 @@ def run(args: argparse.Namespace) -> None:
                 try:
                     we_connect.update(wc)
                     snapshot = extract_all(vehicle)
+                    if snapshot is None:
+                        log.warning("extract_all returned None — skipping this cycle")
+                        continue
                     snapshot = apply_procedural(snapshot)
                     store["records"].append(snapshot)
                     save_store(out, store, args.max_records)

server/network.py

@@ -24,15 +24,17 @@ def _accept_loop(
                 preloaded = store_ref.get("preloaded", [])
 
                 if preloaded:
-                    seen_ts = {r.get("ts") for r in preloaded}
+                    seen_ts = {r.get("ts") for r in preloaded if r is not None}
-                    extra   = [r for r in in_mem if r.get("ts") not in seen_ts]
+                    extra   = [r for r in in_mem if r is not None and r.get("ts") not in seen_ts]
-                    records = sorted(preloaded + extra, key=lambda r: r.get("ts", ""))
+                    records = sorted(preloaded + extra, key=lambda r: r.get("ts", "") if r is not None else "")
                 else:
-                    records = in_mem
+                    records = [r for r in in_mem if r is not None]
 
                 try:
                     prev: dict = {}
                     for record in records:
+                        if record is None:
+                            continue
                         diff = jay_diff_full(prev, record, combine_upd_add=True)
                         prev = record
                         conn.sendall((json.dumps(diff, default=str) + "\n").encode())
@@ -42,6 +44,10 @@ def _accept_loop(
                     log.debug("Failed to send history to %s", addr)
                     conn.close()
                     continue
+                except Exception:
+                    log.exception("Error sending history to %s — dropping client", addr)
+                    conn.close()
+                    continue
                 clients.append(conn)
         except OSError:
             break

server/storage_helpers.py

@@ -53,11 +53,11 @@ def load_last_24h_records(logs_dir: Path, vin: str) -> list:
             try:
                 data = json.loads(path.read_text())
                 if isinstance(data, dict) and "records" in data:
-                    kept = [r for r in data["records"] if r.get("ts", "") >= cutoff_str]
+                    kept = [r for r in data["records"] if r is not None and r.get("ts", "") >= cutoff_str]
                     records.extend(kept)
                     log.debug("Loaded %d/%d records from %s", len(kept), len(data["records"]), path.name)
             except (json.JSONDecodeError, OSError):
                 log.warning("Could not load %s", path)
 
-    records.sort(key=lambda r: r.get("ts", ""))
+    records.sort(key=lambda r: r.get("ts", "") if r is not None else "")
     return records