refactor(ui): delete legacy static website and refresh documentation

docs/client/troubleshooting.md

@@ -78,7 +78,7 @@ code before claiming a root cause is resolved.
 `S2S_DEBUG_PROMPT=true` enables complete prompt logs, including caller information
 and conversation text. Use summaries when full payloads are unnecessary. The
 browser's application functions are module-scoped; do not assume names such as
-`effectiveInstructions()` are available directly on `window` in DevTools.
+`buildInstructions()` are available directly on `window` in DevTools.
 
 ## Short gaps or clipped words around tool results
 
@@ -119,15 +119,17 @@ microphone/audio permissions. If automatic startup fails, use the unlocker
 gesture and inspect the permission error rather than increasing the timer
 without evidence.
 
-## Read-only source checks
+## Local validation
 
-From the repository root, useful syntax checks are:
+From the repository root, run the frontend checks and local backend fixtures:
 
 ```bash
-node --check s2s-client/main.js
-node --check s2s-client/ws/s2s-ws-client.js
-python -m py_compile s2s-client/server.py
+npm --prefix s2s-frontend run check
+npm --prefix s2s-frontend run build
+.venv/bin/python -m unittest discover -s s2s-client/tests -v
 ```
 
-Syntax checks do not validate microphone access, network services, model output,
-or audio quality. Collect a fresh browser/backend reproduction for those paths.
+These checks cover frontend contracts and local session/queue/WebSocket
+fixtures. They do not validate deployed services, real microphone hardware,
+model output, or audio quality. Use a local browser/backend reproduction for
+those paths before deployment.