fix: configure gitea webhook auto-deploy, fix NVS CRC, and improve flash UI

- Add deploy-host.sh for webhook-triggered docker redeploy
- Update docker-compose.yml and nginx.conf for auto-pull setup
- Fix vite.config.js and admin router for deployment environment
- Fix NVS CRC seed to use 0xFFFFFFFF to match esp_rom_crc32_le
- Add dual-panel flash UI: esptool log + live 115200 serial monitor
- Auto-reset device via RTS after flash (no manual power cycle needed)
- Clean up Header.jsx debug title text

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -10,6 +10,8 @@ services:
       - ./data/built_melodies:/app/storage/built_melodies
       - ./data/firmware:/app/storage/firmware
       - ./data/firebase-service-account.json:/app/firebase-service-account.json:ro
+      # Auto-deploy: project root so container can write the trigger file
+      - /home/bellsystems/bellsystems-cp:/home/bellsystems/bellsystems-cp
     ports:
       - "8000:8000"
     depends_on: []