Share the saved admin password across ESP32 management services

Use the committed node credential for setup WiFi, WebConfig and browser OTA. Add persistent ESP32 WiFi Companion management credentials without changing preferences layouts, revoke stale browser sessions on rotation, retain scoped save receipts, and coordinate credential changes with flash uploads. Keep external-service credentials and trusted TCP protocol compatibility independent. Update live join QR codes, failure handling and documentation.

Validated 51 native cases, 158 related host and browser methods, and serial Full V4 Companion, Station G3 Repeater, ESP32-C6 Room Server and V4 Sensor firmware builds.

scripts/esp32_async_web_fix.py

@@ -46,6 +46,11 @@ def replace_async_source(build_env, node):
     if not destination.exists() or destination.read_text(encoding="ascii") != content:
         destination.write_text(content, encoding="ascii")
     build_env.PrependUnique(CPPPATH=[str(include_dir)])
+    if source.name == "AsyncElegantOTA.cpp":
+        # PlatformIO compiles libraries in cloned environments which need not
+        # inherit the application src include path. The current uploader uses
+        # the shared runtime management credential header from that directory.
+        build_env.AppendUnique(CPPPATH=[build_env.subst("$PROJECT_SRC_DIR")])
     return build_env.File(str(destination))