chore: add Biome for formatting and linting (#116)

- Add Biome as formatter and linter (replaces Prettier)
- Configure Husky + lint-staged for pre-commit hooks
- Add VS Code settings for format on save
- Ignore components/ui/ (shadcn generated code)
- Remove semicolons, use 4-space indent
- Reformat all files to new style

lib/langfuse.ts

@@ -1,95 +1,107 @@
-import { observe, updateActiveTrace } from '@langfuse/tracing';
-import { LangfuseClient } from '@langfuse/client';
-import * as api from '@opentelemetry/api';
+import { LangfuseClient } from "@langfuse/client"
+import { observe, updateActiveTrace } from "@langfuse/tracing"
+import * as api from "@opentelemetry/api"
 
 // Singleton LangfuseClient instance for direct API calls
-let langfuseClient: LangfuseClient | null = null;
+let langfuseClient: LangfuseClient | null = null
 
 export function getLangfuseClient(): LangfuseClient | null {
-  if (!process.env.LANGFUSE_PUBLIC_KEY || !process.env.LANGFUSE_SECRET_KEY) {
-    return null;
-  }
+    if (!process.env.LANGFUSE_PUBLIC_KEY || !process.env.LANGFUSE_SECRET_KEY) {
+        return null
+    }
 
-  if (!langfuseClient) {
-    langfuseClient = new LangfuseClient({
-      publicKey: process.env.LANGFUSE_PUBLIC_KEY,
-      secretKey: process.env.LANGFUSE_SECRET_KEY,
-      baseUrl: process.env.LANGFUSE_BASEURL,
-    });
-  }
+    if (!langfuseClient) {
+        langfuseClient = new LangfuseClient({
+            publicKey: process.env.LANGFUSE_PUBLIC_KEY,
+            secretKey: process.env.LANGFUSE_SECRET_KEY,
+            baseUrl: process.env.LANGFUSE_BASEURL,
+        })
+    }
 
-  return langfuseClient;
+    return langfuseClient
 }
 
 // Check if Langfuse is configured
 export function isLangfuseEnabled(): boolean {
-  return !!process.env.LANGFUSE_PUBLIC_KEY;
+    return !!process.env.LANGFUSE_PUBLIC_KEY
 }
 
 // Update trace with input data at the start of request
 export function setTraceInput(params: {
-  input: string;
-  sessionId?: string;
-  userId?: string;
+    input: string
+    sessionId?: string
+    userId?: string
 }) {
-  if (!isLangfuseEnabled()) return;
+    if (!isLangfuseEnabled()) return
 
-  updateActiveTrace({
-    name: 'chat',
-    input: params.input,
-    sessionId: params.sessionId,
-    userId: params.userId,
-  });
+    updateActiveTrace({
+        name: "chat",
+        input: params.input,
+        sessionId: params.sessionId,
+        userId: params.userId,
+    })
 }
 
 // Update trace with output and end the span
-export function setTraceOutput(output: string, usage?: { promptTokens?: number; completionTokens?: number }) {
-  if (!isLangfuseEnabled()) return;
+export function setTraceOutput(
+    output: string,
+    usage?: { promptTokens?: number; completionTokens?: number },
+) {
+    if (!isLangfuseEnabled()) return
 
-  updateActiveTrace({ output });
+    updateActiveTrace({ output })
 
-  const activeSpan = api.trace.getActiveSpan();
-  if (activeSpan) {
-    // Manually set usage attributes since AI SDK Bedrock streaming doesn't provide them
-    if (usage?.promptTokens) {
-      activeSpan.setAttribute('ai.usage.promptTokens', usage.promptTokens);
-      activeSpan.setAttribute('gen_ai.usage.input_tokens', usage.promptTokens);
+    const activeSpan = api.trace.getActiveSpan()
+    if (activeSpan) {
+        // Manually set usage attributes since AI SDK Bedrock streaming doesn't provide them
+        if (usage?.promptTokens) {
+            activeSpan.setAttribute("ai.usage.promptTokens", usage.promptTokens)
+            activeSpan.setAttribute(
+                "gen_ai.usage.input_tokens",
+                usage.promptTokens,
+            )
+        }
+        if (usage?.completionTokens) {
+            activeSpan.setAttribute(
+                "ai.usage.completionTokens",
+                usage.completionTokens,
+            )
+            activeSpan.setAttribute(
+                "gen_ai.usage.output_tokens",
+                usage.completionTokens,
+            )
+        }
+        activeSpan.end()
     }
-    if (usage?.completionTokens) {
-      activeSpan.setAttribute('ai.usage.completionTokens', usage.completionTokens);
-      activeSpan.setAttribute('gen_ai.usage.output_tokens', usage.completionTokens);
-    }
-    activeSpan.end();
-  }
 }
 
 // Get telemetry config for streamText
 export function getTelemetryConfig(params: {
-  sessionId?: string;
-  userId?: string;
+    sessionId?: string
+    userId?: string
 }) {
-  if (!isLangfuseEnabled()) return undefined;
+    if (!isLangfuseEnabled()) return undefined
 
-  return {
-    isEnabled: true,
-    // Disable automatic input recording to avoid uploading large base64 images to Langfuse media
-    // User text input is recorded manually via setTraceInput
-    recordInputs: false,
-    recordOutputs: true,
-    metadata: {
-      sessionId: params.sessionId,
-      userId: params.userId,
-    },
-  };
+    return {
+        isEnabled: true,
+        // Disable automatic input recording to avoid uploading large base64 images to Langfuse media
+        // User text input is recorded manually via setTraceInput
+        recordInputs: false,
+        recordOutputs: true,
+        metadata: {
+            sessionId: params.sessionId,
+            userId: params.userId,
+        },
+    }
 }
 
 // Wrap a handler with Langfuse observe
 export function wrapWithObserve<T>(
-  handler: (req: Request) => Promise<T>
+    handler: (req: Request) => Promise<T>,
 ): (req: Request) => Promise<T> {
-  if (!isLangfuseEnabled()) {
-    return handler;
-  }
+    if (!isLangfuseEnabled()) {
+        return handler
+    }
 
-  return observe(handler, { name: 'chat', endOnExit: false });
+    return observe(handler, { name: "chat", endOnExit: false })
 }