接入Gitea Actions蓝绿发布：API_KEY构建时注入、新增Dockerfile

- src/config.js 的 API_KEY 改为从构建时环境变量 TINODE_API_KEY 注入，
  不再依赖官方demo默认值；未设置时保留原demo key作为本地快速测试的兜底
- webpack.config.js 新增 DefinePlugin 完成注入，并自动加载(gitignored的)
  .env.local，开发者本地调试不需要每次手动export
- 新增 Dockerfile(node构建+nginx serve) 和 docker/nginx.conf
- 新增 .gitea/workflows/deploy.yml：手动触发的蓝绿发布流程

webpack.config.js

@@ -1,6 +1,20 @@
 const CopyPlugin = require('copy-webpack-plugin');
+const webpack = require('webpack');
+const fs = require('fs');
 const path = require('path');
 
+// Load developer-local overrides (gitignored) so `npm run build` picks up
+// TINODE_API_KEY etc. without having to export them by hand every time.
+const envLocalPath = path.resolve(__dirname, '.env.local');
+if (fs.existsSync(envLocalPath)) {
+  for (const line of fs.readFileSync(envLocalPath, 'utf8').split('\n')) {
+    const match = line.match(/^\s*([A-Z_][A-Z0-9_]*)\s*=\s*(.*)\s*$/);
+    if (match) {
+      process.env[match[1]] = process.env[match[1]] || match[2];
+    }
+  }
+}
+
 module.exports = (env, argv) => {
   const mode = argv.mode === 'production' ? 'prod' : 'dev';
   const maxAssetSize = mode === 'prod' ? 360000 : 1512000;
@@ -52,6 +66,11 @@ module.exports = (env, argv) => {
           { from: `node_modules/tinode-sdk/umd/tinode.${mode}.js.map`, to: `tinode.${mode}.js.map` },
         ],
       }),
+      // Bakes TINODE_API_KEY (from the environment or .env.local) into the bundle at build
+      // time. See src/config.js for the fallback used when it's not set.
+      new webpack.DefinePlugin({
+        'process.env.TINODE_API_KEY': JSON.stringify(process.env.TINODE_API_KEY || ''),
+      }),
     ],
     externals: {
       'livekit-client': 'LivekitClient',