Update chat events/transcription flow and container startup fixes

Frontend/server/utils/langfuse.ts

@@ -0,0 +1,29 @@
+import { Langfuse } from "langfuse";
+
+let client: Langfuse | null = null;
+
+function isTruthy(value: string | undefined) {
+  const v = (value ?? "").trim().toLowerCase();
+  return v === "1" || v === "true" || v === "yes" || v === "on";
+}
+
+export function isLangfuseEnabled() {
+  const enabledRaw = process.env.LANGFUSE_ENABLED;
+  if (enabledRaw && !isTruthy(enabledRaw)) return false;
+  return Boolean((process.env.LANGFUSE_PUBLIC_KEY ?? "").trim() && (process.env.LANGFUSE_SECRET_KEY ?? "").trim());
+}
+
+export function getLangfuseClient() {
+  if (!isLangfuseEnabled()) return null;
+  if (client) return client;
+
+  client = new Langfuse({
+    publicKey: (process.env.LANGFUSE_PUBLIC_KEY ?? "").trim(),
+    secretKey: (process.env.LANGFUSE_SECRET_KEY ?? "").trim(),
+    baseUrl: (process.env.LANGFUSE_BASE_URL ?? "http://langfuse-web:3000").trim(),
+    enabled: true,
+  });
+
+  return client;
+}
+