Add jam strategies (direct/precision/flood), web UI modes and SmartRF register export/import

- JamMode: DIRECT, PRECISION, FLOOD with NVS persistence and flood tick path
- HTTP: POST /api/jam_mode, GET/POST /api/cc1101/registers
- Telemetry: jam_mode, jam_mode_str
- Web UI: mode buttons, toast on switch, CC1101 hex export/apply card
- config.h: precision/flood tuning, CC1101_CFG_REG_LAST
- platformio.ini: explicit USB serial upload port for macOS

Made-with: Cursor

platformio.ini

@@ -27,3 +27,5 @@ board_build.extra_flags =
   -DBOARD_HAS_PSRAM
 
 monitor_speed = 115200
+; Avoid macOS picking Bluetooth “serial” instead of the ESP32 USB-UART
+upload_port = /dev/cu.usbserial-A5069RR4