Align docs with ESP32-S3 dashboard architecture

docs/dashboard-esp32s3.md

@@ -29,21 +29,18 @@ Primary transport:
 - HTTP JSON API
 
 Not required for normal dashboard operation:
-- Pico UART
 - MicroPython display drivers
 - CAT5e UART data pair
 
-UART JSON remains useful for future diagnostics, alternate displays, or debug clients.
+UART JSON remains useful for diagnostics, alternate displays, or debug clients, but it is not part of the planned dashboard path.
 
 ## Power
 
 Dashboard power path:
 
-Cargo area 12V
-→ CAT5e power pair(s)
-→ Dash enclosure
-→ Buck converter
-→ 5V dashboard input
+ACC switched 12V
+-> fuse
+-> Waveshare VIN
 
 All grounds remain common.
 
@@ -149,8 +146,6 @@ Later:
 - WebUI Config tab remains the preferred setup workflow.
 - Cargo ESP32 should continue to work without the dashboard powered on.
 
-## Deferred Pico Path
+## Out of Scope
 
-The Pico 2 W dashboard plan is deferred.
-
-Keep existing UART protocol docs because UART remains useful, but new dashboard work should target the ESP32-S3 display first.
+No Pico dashboard is planned. Existing Pico/UART material is legacy unless explicitly revived for diagnostics or alternate hardware.