feat: Add VHF DSC Channel 70 monitoring and decoding

- Implement DSC message decoding (Distress, Urgency, Safety, Routine)

- Add MMSI country identification via MID lookup

- Integrate position extraction and map markers for distress alerts

- Implement device conflict detection to prevent SDR collisions with AIS

- Add permanent storage for critical alerts and visual UI overlays

routes/__init__.py

@@ -11,6 +11,7 @@ def register_blueprints(app):
     from .bluetooth_v2 import bluetooth_v2_bp
     from .adsb import adsb_bp
     from .ais import ais_bp
+    from .dsc import dsc_bp
     from .acars import acars_bp
     from .aprs import aprs_bp
     from .satellite import satellite_bp
@@ -30,6 +31,7 @@ def register_blueprints(app):
     app.register_blueprint(bluetooth_v2_bp)  # New unified Bluetooth API
     app.register_blueprint(adsb_bp)
     app.register_blueprint(ais_bp)
+    app.register_blueprint(dsc_bp)  # VHF DSC maritime distress
     app.register_blueprint(acars_bp)
     app.register_blueprint(aprs_bp)
     app.register_blueprint(satellite_bp)