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>

backend/utils/nvs_generator.py

@@ -60,7 +60,8 @@ ENTRY_TYPE_STRING    = 0x21
 
 
 def _crc32(data: bytes) -> int:
-    return binascii.crc32(data) & 0xFFFFFFFF
+    # ESP-IDF uses 0xFFFFFFFF as the initial CRC seed (matches esp_rom_crc32_le)
+    return binascii.crc32(data, 0xFFFFFFFF) & 0xFFFFFFFF
 
 
 def _page_header_crc(seq: int, version: int) -> int: