feat(bridge): add wifi/serial bridge runtime and UI

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/API.md

@@ -3,7 +3,7 @@
 This document covers:
 
 1. **HTTP and WebSocket** exposed by the Raspberry Pi app (`src/main.py`) — profiles, zones, presets, transport send, pattern OTA helpers, and related resources.
-2. **LED driver JSON** — the compact **v1** message format. It is sent over the **serial → ESP-NOW bridge** to ESP32 peers and as **single JSON text messages** over the **outbound WebSocket** to **Wi-Fi** drivers (same logical fields).
+2. **LED driver JSON** — the compact **v1** message format. It is sent over the **ESP-NOW bridge** (WebSocket) to ESP32 peers and as **single JSON text messages** over the **outbound WebSocket** to **Wi-Fi** drivers (same logical fields).
 
 Default HTTP listen address: `0.0.0.0`. Port defaults to **80**; override with the **`PORT`** environment variable (see `pipenv run run`).
 
@@ -52,7 +52,7 @@ Profiles are selected with **`POST /profiles/<id>/apply`**, which sets `current_
 
 Connect to **`ws://<host>:<port>/ws`**.
 
-- Send **JSON**: the object is forwarded through the **serial sender** (6-byte MAC prefix + payload to the ESP-NOW bridge). Optional key **`to`**: 12-character hex MAC address; if present it is removed from the object and the payload is sent to that peer; otherwise the default destination from settings is used.
+- Send **JSON**: the object is forwarded through the **ESP-NOW bridge** (devices envelope or legacy MAC-prefixed payload). Optional key **`to`**: 12-character hex MAC address; if present it is removed from the object and the payload is sent to that peer; otherwise the default destination from settings is used.
 - Send **non-JSON text**: forwarded as raw bytes with the default address.
 - On send failure, the server may reply with `{"error": "Send failed"}`.