feat(assets): embed LCD and audio resources in OTA app

docs/architecture-and-flow-mermaid.md

@@ -52,7 +52,7 @@ flowchart LR
         LCD["ST7789 direct LCD backend"]
         Audio["ES8311 audio pipeline"]
         Network["Wi-Fi, BLE provisioning, HTTP, WebSocket"]
-        Storage["NVS, LittleFS"]
+        Storage["NVS, embedded assets, model partition"]
         GPIO["GPIO, stepper, console UART"]
     end
 
@@ -187,7 +187,7 @@ flowchart LR
     PlatformReq["platform_lcd_request_presentation()"]
     Pending["lcd_direct pending request"]
     Render["cp_lcd_render loop"]
-    Draw["decode PNG asset frame\nfrom /littlefs/lcd"]
+    Draw["decode PNG asset frame\nfrom embedded app image"]
     Panel["ST7789 panel"]
 
     CP --> DomainReq --> Resolve --> Catalog --> PlatformReq --> Pending --> Render --> Draw --> Panel