perf: 优化内存与遥测管理，启用 Vite minify

- 禁用 HISTORY_SNIP feature flag 并新增 proactiveTruncate 防止无 compact_boundary 时内存无限增长
- 跳过未启用 telemetry 时的 OTel 初始化，防止长会话 PerformanceMeasure 堆积
- OTel 导出遇 401/403 自动关闭 reader，防止 handle 泄漏
- Vite 构建启用 minify

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/utils/telemetry/instrumentation.ts

@@ -206,10 +206,49 @@ async function getOtlpReaders() {
 
   return exporters.map(exporter => {
     if ('export' in exporter) {
-      return new PeriodicExportingMetricReader({
+      const reader = new PeriodicExportingMetricReader({
         exporter,
         exportIntervalMillis: exportInterval,
       })
+      // Wrap the export callback to auto-shutdown the reader on auth
+      // failures (401/403). Without this the PeriodicExportingMetricReader's
+      // internal setInterval keeps retrying forever, leaking handles.
+      const originalExport = (
+        exporter as unknown as {
+          export: (
+            metrics: unknown,
+            callback: (result: { error?: Error }) => void,
+          ) => unknown
+        }
+      ).export.bind(exporter)
+      ;(
+        exporter as unknown as {
+          export: (
+            metrics: unknown,
+            callback: (result: { error?: Error }) => void,
+          ) => unknown
+        }
+      ).export = (metrics, callback) => {
+        return originalExport(metrics, result => {
+          if (result.error) {
+            const msg = result.error.message || ''
+            if (
+              msg.includes('401') ||
+              msg.includes('403') ||
+              msg.includes('Unauthorized') ||
+              msg.includes('authentication')
+            ) {
+              logForDebugging(
+                `[3P telemetry] Auth error detected, shutting down metric reader`,
+                { level: 'error' },
+              )
+              void reader.shutdown()
+            }
+          }
+          callback(result)
+        })
+      }
+      return reader
     }
     return exporter
   })