Add CI/CD pipelines, NSIS installer, ES module bundling, and ruff linting

- Add Gitea Actions workflows: test.yml (lint + test on push/PR) and
  release.yml (build + NSIS installer + upload on v* tags)
- Add NSIS installer with optional desktop shortcut and auto-start
- Add esbuild bundler: ES module migration with IIFE bundle output
- Add build-dist-windows.sh for cross-building Windows distribution
- Fix all ruff lint errors (import sorting, unused imports, line length)
- Remove redundant scripts (start-server.bat, stop-server.bat,
  start-server-background.vbs)
- Update CLAUDE.md with CI/CD and release documentation

media_server/static/js/websocket.js

@@ -2,11 +2,21 @@
 // WebSocket: Connection, reconnection, authentication
 // ============================================================
 
+import {
+    dom, t, showToast, setWs,
+    WS_BACKOFF_BASE_MS, WS_BACKOFF_MAX_MS,
+    WS_MAX_RECONNECT_ATTEMPTS, WS_PING_INTERVAL_MS,
+} from './core.js';
+import { updateUI, visualizerEnabled, visualizerAvailable, setFrequencyData, stopPositionInterpolation, loadAudioDevices } from './player.js';
+import { loadScripts, loadScriptsTable, displayQuickAccess } from './scripts.js';
+import { loadCallbacksTable } from './callbacks.js';
+import { loadHeaderLinks, loadLinksTable } from './links.js';
+
 let reconnectTimeout = null;
 let pingInterval = null;
 let wsReconnectAttempts = 0;
 
-function showAuthForm(errorMessage = '') {
+export function showAuthForm(errorMessage = '') {
     const overlay = document.getElementById('auth-overlay');
     overlay.classList.remove('hidden');
 
@@ -23,7 +33,7 @@ function hideAuthForm() {
     document.getElementById('auth-overlay').classList.add('hidden');
 }
 
-function authenticate() {
+export function authenticate() {
     const token = document.getElementById('token-input').value.trim();
     if (!token) {
         showAuthForm(t('auth.required'));
@@ -34,15 +44,18 @@ function authenticate() {
     connectWebSocket(token);
 }
 
-function clearToken() {
+export function clearToken() {
     localStorage.removeItem('media_server_token');
-    if (ws) {
-        ws.close();
-    }
+    // Access ws via import
+    import('./core.js').then(core => {
+        if (core.ws) {
+            core.ws.close();
+        }
+    });
     showAuthForm(t('auth.cleared'));
 }
 
-function connectWebSocket(token) {
+export function connectWebSocket(token) {
     if (pingInterval) {
         clearInterval(pingInterval);
         pingInterval = null;
@@ -51,9 +64,10 @@ function connectWebSocket(token) {
     const protocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:';
     const wsUrl = `${protocol}//${window.location.host}/api/media/ws?token=${encodeURIComponent(token)}`;
 
-    ws = new WebSocket(wsUrl);
+    const newWs = new WebSocket(wsUrl);
+    setWs(newWs);
 
-    ws.onopen = () => {
+    newWs.onopen = () => {
         console.log('WebSocket connected');
         wsReconnectAttempts = 0;
         updateConnectionStatus(true);
@@ -66,11 +80,11 @@ function connectWebSocket(token) {
         loadHeaderLinks();
         loadAudioDevices();
         if (visualizerEnabled && visualizerAvailable) {
-            ws.send(JSON.stringify({ type: 'enable_visualizer' }));
+            newWs.send(JSON.stringify({ type: 'enable_visualizer' }));
         }
     };
 
-    ws.onmessage = (event) => {
+    newWs.onmessage = (event) => {
         const msg = JSON.parse(event.data);
 
         if (msg.type === 'status' || msg.type === 'status_update') {
@@ -85,18 +99,18 @@ function connectWebSocket(token) {
             loadLinksTable();
             displayQuickAccess();
         } else if (msg.type === 'audio_data') {
-            frequencyData = msg.data;
+            setFrequencyData(msg.data);
         } else if (msg.type === 'error') {
             console.error('WebSocket error:', msg.message);
         }
     };
 
-    ws.onerror = (error) => {
+    newWs.onerror = (error) => {
         console.error('WebSocket error:', error);
         updateConnectionStatus(false);
     };
 
-    ws.onclose = (event) => {
+    newWs.onclose = (event) => {
         console.log('WebSocket closed:', event.code);
         updateConnectionStatus(false);
         stopPositionInterpolation();
@@ -131,13 +145,13 @@ function connectWebSocket(token) {
     };
 
     pingInterval = setInterval(() => {
-        if (ws && ws.readyState === WebSocket.OPEN) {
-            ws.send(JSON.stringify({ type: 'ping' }));
+        if (newWs && newWs.readyState === WebSocket.OPEN) {
+            newWs.send(JSON.stringify({ type: 'ping' }));
         }
     }, WS_PING_INTERVAL_MS);
 }
 
-function updateConnectionStatus(connected) {
+export function updateConnectionStatus(connected) {
     if (connected) {
         dom.statusDot.classList.add('connected');
     } else {
@@ -159,7 +173,7 @@ function hideConnectionBanner() {
     banner.classList.add('hidden');
 }
 
-function manualReconnect() {
+export function manualReconnect() {
     const savedToken = localStorage.getItem('media_server_token');
     if (savedToken) {
         wsReconnectAttempts = 0;