feat: make MikroTik blocklist cumulative via git history

app/web.py

@@ -348,7 +348,12 @@ def create_app() -> Flask:
 
     @app.post("/api/firewall/apply")
     def firewall_apply():
-        """Apply the blocklist sync (add new / remove stale entries)."""
+        """Apply the blocklist sync (cumulative — adds new entries only).
+
+        The blocklist is grow-only: it adds entries present in the complete
+        set (git history + working files + scan targets) and only prunes
+        router entries never seen in any git version of the blocklist files.
+        """
         return _sync_firewall(dry_run=False)
 
     # --- whitelist ---------------------------------------------------------