Refactor: Remove NFStream and flow identity utilities; introduce Tshark manager

- Deleted flow_identity.py and nfstream_flow_worker.py as they are no longer needed.
- Removed nfstream_manager.py and its associated logic for managing NFStream workers.
- Added tshark_manager.py to manage tshark packet enrichment and matching.
- Updated setup_build_server.sh to include default environment variables for tshark.
- Implemented packet signature generation and enrichment logic in the new TsharkManager class.

backend/src/network_sniffer.py

@@ -33,9 +33,9 @@ from src.utilities.interface_bridge_helpers import (
 )
 from src.config import settings
 from src.utilities.bridge_telemetry import bridge_telemetry_manager
-from src.utilities.nfstream_manager import nfstream_manager
 from src.utilities.packet_identity import build_packet_uid
 from src.utilities.packet_tracker import packet_tracker
+from src.utilities.tshark_manager import tshark_manager
 from src.Models.etherType import EtherTypeEnum, ethertype_from_int
 from src.Models.ip_protocol import IPProtocolEnum, protocol_from_number
 
@@ -371,13 +371,13 @@ def parse_packet(pkt, bridge_label: str, capture_metadata: Optional[Dict[str, An
     if Raw in pkt and not pkt_info.get("protocol_name"):
         pkt_info["protocol_name"] = "RAW"
 
-    # Flow-level enrichment using NFStream, if available.
+    # Packet-level enrichment using tshark, if available.
     try:
-        flow_info = nfstream_manager.lookup_packet(pkt, pkt_iface)
-        if flow_info:
-            _merge_enrichment(pkt_info, flow_info)
+        packet_info = tshark_manager.lookup_packet(pkt, pkt_iface)
+        if packet_info:
+            _merge_enrichment(pkt_info, packet_info)
     except Exception:
-        logger.exception("NFStream enrichment failed")
+        logger.exception("tshark enrichment failed")
 
     if ICMP in pkt:
         inner = pkt[ICMP].payload
@@ -536,9 +536,9 @@ def _sync_bridge_telemetry() -> None:
         }
     )
     try:
-        nfstream_manager.update_interfaces(active_enrichment_ifaces)
+        tshark_manager.update_interfaces(active_enrichment_ifaces)
     except Exception:
-        logger.exception("Failed to update NFStream enrichment workers")
+        logger.exception("Failed to update tshark enrichment workers")
 
 
 # -------------------------
@@ -839,6 +839,6 @@ def get_internal_debug_state() -> dict:
         "buffer_len": len(_PACKET_BUFFER),
         "bridge_capture_mode": "tc_ingress_raw" if any(s.get("is_bridge") for s in sessions.values()) else "af_packet",
         "telemetry_ports": sorted({iface for session in sessions.values() for iface in session.get("ports", [])}),
-        "nfstream": nfstream_manager.get_debug_snapshot(),
+        "tshark": tshark_manager.get_debug_snapshot(),
         "packet_tracker": packet_tracker.get_debug_snapshot(),
     }