feat: implement automatic bulk sync for blockchain nodes

- Add auto_sync_enabled, auto_sync_threshold, auto_sync_max_retries config
- Add min_bulk_sync_interval for rate limiting
- Implement gap detection in process_blocks() with automatic bulk sync trigger
- Add rate limiting to ChainSync.bulk_import_from() to prevent sync loops
- Automatic bulk sync triggers when gap > threshold (default 10 blocks)
- Retries block import after bulk sync completes
- Logs sync events for monitoring and debugging

apps/blockchain-node/src/aitbc_chain/config.py

@@ -68,6 +68,12 @@ class ChainSettings(BaseSettings):
     trusted_proposers: str = ""  # comma-separated list of trusted proposer IDs
     max_reorg_depth: int = 10  # max blocks to reorg on conflict
     sync_validate_signatures: bool = True  # validate proposer signatures on import
+    
+    # Automatic bulk sync settings
+    auto_sync_enabled: bool = True  # enable automatic bulk sync when gap detected
+    auto_sync_threshold: int = 10  # blocks gap threshold to trigger bulk sync
+    auto_sync_max_retries: int = 3  # max retry attempts for automatic bulk sync
+    min_bulk_sync_interval: int = 60  # minimum seconds between bulk sync attempts
 
     gossip_backend: str = "memory"
     gossip_broadcast_url: Optional[str] = None