Add rtlamr utility meter monitoring support

- Added rtlamr mode for decoding utility meters (water, gas, electric)
- Starts rtl_tcp server first, then connects rtlamr to it
- Supports multiple message types: SCM, SCM+, IDM, NetIDM, R900, R900 BCD
- Added frequency presets for 912 MHz (NA) and 868 MHz (EU)
- Includes meter ID filtering and unique message options
- Updated setup.sh to check and install rtlamr and rtl_tcp
- Added UI components: navigation button, mode template, JavaScript functions
- Integrated into SDR/RF dropdown menu with lightning bolt icon
- Updates mode indicator with frequency when listening
- Added help documentation and requirements section

routes/__init__.py

@@ -4,6 +4,7 @@ def register_blueprints(app):
     """Register all route blueprints with the Flask app."""
     from .pager import pager_bp
     from .sensor import sensor_bp
+    from .rtlamr import rtlamr_bp
     from .wifi import wifi_bp
     from .bluetooth import bluetooth_bp
     from .adsb import adsb_bp
@@ -18,6 +19,7 @@ def register_blueprints(app):
 
     app.register_blueprint(pager_bp)
     app.register_blueprint(sensor_bp)
+    app.register_blueprint(rtlamr_bp)
     app.register_blueprint(wifi_bp)
     app.register_blueprint(bluetooth_bp)
     app.register_blueprint(adsb_bp)