feat: service console auto-connect, settings panel, and batch of enhancements

- Auto-connect WebSocket on page load in service console
- Settings modal for editing sgclaw_config.json (API key, base URL, model, skills dir, etc.)
- UpdateConfig/ConfigUpdated protocol messages for remote config save
- save_to_path() for SgClawSettings serialization
- ConfigUpdated handler in sg_claw_client binary
- Protocol serialization tests for new message types
- HTML test assertions for auto-connect and settings UI
- Additional pending changes: deterministic submit, org units, lineloss xlsx export, browser script tool, and docs

🤖 Generated with [Qoder][https://qoder.com]

tests/service_console_html_test.rs

@@ -24,4 +24,14 @@ fn service_console_html_stays_on_service_ws_boundary() {
     assert!(!source.contains("/sgclaw/callback/commands/next"));
     assert!(!source.contains("/sgclaw/callback/commands/ack"));
     assert!(!source.contains("ws://127.0.0.1:12345"));
+
+    // Auto-connect and settings enhancement assertions
+    assert!(source.contains("DOMContentLoaded"));
+    assert!(source.contains("settingsBtn"));
+    assert!(source.contains("settingsModal"));
+    assert!(source.contains("update_config"));
+    assert!(source.contains("config_updated"));
+    assert!(source.contains("settingApiKey"));
+    assert!(source.contains("settingBaseUrl"));
+    assert!(source.contains("settingModel"));
 }