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

esbuild.mjs

@@ -0,0 +1,26 @@
+import * as esbuild from 'esbuild';
+
+const srcDir = 'media_server/static';
+const outDir = `${srcDir}/dist`;
+
+const watch = process.argv.includes('--watch');
+
+/** @type {esbuild.BuildOptions} */
+const jsOpts = {
+    entryPoints: [`${srcDir}/js/app.js`],
+    bundle: true,
+    format: 'iife',
+    outfile: `${outDir}/app.bundle.js`,
+    minify: true,
+    sourcemap: true,
+    target: ['es2020'],
+    logLevel: 'info',
+};
+
+if (watch) {
+    const jsCtx = await esbuild.context(jsOpts);
+    await jsCtx.watch();
+    console.log('Watching for changes...');
+} else {
+    await esbuild.build(jsOpts);
+}