Fix uvicorn logging error in PyInstaller builds

Set log_config=None to disable uvicorn's default logging configuration
which fails in frozen executables with "Unable to configure formatter 'default'"

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

web_server.py

@@ -252,7 +252,8 @@ class WebServer:
             self.app,
             host="0.0.0.0",
             port=self.port,
-            log_level="warning"
+            log_level="warning",
+            log_config=None  # Disable default logging config for PyInstaller compatibility
         )
         self.server = uvicorn.Server(config)
         self.server.run()
@@ -271,7 +272,8 @@ class WebServer:
             self.app,
             host="0.0.0.0",
             port=self.port,
-            log_level="warning"
+            log_level="warning",
+            log_config=None  # Disable default logging config for PyInstaller compatibility
         )
         self.server = uvicorn.Server(config)
         await self.server.serve()