Standardize API UART parity and update docs

docs/ARCHITECTURE.md

@@ -233,3 +233,99 @@ Possible future integrations:
 - OTA updates
 
 All future integrations should consume the same generic status/config model.
+
+---
+
+## Networking Architecture
+
+### Current Network Mode
+
+The ESP32 currently runs in Access Point mode.
+
+Default access:
+
+    http://192.168.4.1
+
+The AP is the recovery/setup network.
+
+### Planned Network Mode
+
+The planned long-term network mode is AP + STA.
+
+AP mode:
+
+    Always available
+    Used for recovery and direct setup
+
+STA mode:
+
+    Connects to a configured WiFi network
+    Used for camp/home access from phone or laptop
+
+Example networks:
+
+    Starlink
+    Home WiFi
+    Shop WiFi
+
+### Multiple WiFi Profiles
+
+The ESP32 should eventually store multiple WiFi profiles and try them in priority order.
+
+Example:
+
+    1. Starlink
+    2. Home WiFi
+    3. Shop WiFi
+
+Expected behavior:
+
+    Start AP first
+    Try configured STA networks
+    Connect to the first available network
+    Keep AP available even after STA connects
+
+Reason:
+
+- Starlink may be off
+- Home WiFi may only be available in the driveway
+- AP must remain available for recovery
+- User should not lose access because of a bad WiFi password
+
+### Phone Dashboard Access
+
+When connected to the ESP32 AP:
+
+    http://192.168.4.1
+
+When connected through Starlink/home WiFi:
+
+    http://controller-ip
+
+Future mDNS target:
+
+    http://overland-controller.local
+
+### Dashboard Roles
+
+ESP32:
+
+    Source of truth
+    Lightweight phone dashboard
+    HTTP API
+    Recovery AP
+
+Pico 2 W:
+
+    Instant physical dashboard
+    UART client
+    Touchscreen UI
+
+Optional future Pi Zero:
+
+    Advanced web dashboard
+    Logging
+    Charts
+    Integrations
+
+The Pi Zero should be optional, not required for core operation.