fix: initialize default production LLM provider client (#393)

src/lib/llm/router.test.ts

@@ -6,7 +6,10 @@ beforeEach(() => {
   vi.useFakeTimers();
   vi.setSystemTime(new Date('2026-05-12T00:00:00Z'));
 });
-afterEach(() => vi.useRealTimers());
+afterEach(() => {
+  __setLlmProvider(null);
+  vi.useRealTimers();
+});
 
 const schema = z.object({ ok: z.boolean(), answer: z.string() });
 
@@ -69,4 +72,11 @@ describe('llmCall', () => {
     expect(r.ok).toBe(true);
     if (r.ok) expect(r.data.answer).toBe('yo');
   });
+
+  it('falls back to default provider or returns unavailable when override is cleared', async () => {
+    __setLlmProvider(null);
+    const r = await llmCall({ prompt: 'noop', schema });
+    expect(r.ok).toBe(false);
+    if (!r.ok) expect(r.error.code).toBe('llm_unavailable');
+  });
 });

src/lib/llm/router.ts

@@ -1,4 +1,5 @@
 import { z } from 'zod';
+import Groq from 'groq-sdk';
 import type { Result } from '../result';
 import { ok, err } from '../result';
 
@@ -25,14 +26,32 @@ type LlmCallArgs<T> = {
   schema: z.ZodType<T>;
 };
 
+const groqApiKey = process.env.GROQ_API_KEY;
+
+const groqProvider: LlmProvider = {
+  name: 'groq',
+  complete: async (prompt: string) => {
+    if (!groqApiKey) {
+      throw new Error('GROQ_API_KEY is not set');
+    }
+    const groq = new Groq({ apiKey: groqApiKey });
+    const completion = await groq.chat.completions.create({
+      messages: [{ role: 'user', content: prompt }],
+      model: 'llama3-8b-8192',
+    });
+    return completion.choices[0]?.message?.content ?? '';
+  },
+  isHealthy: () => !!groqApiKey,
+};
+
 let providerOverride: LlmProvider | null = null;
 
 export function __setLlmProvider(p: LlmProvider | null): void {
   providerOverride = p;
 }
 
 function pickProvider(): LlmProvider | null {
-  return providerOverride;
+  return providerOverride || (groqApiKey ? groqProvider : null);
 }
 
 function extractJson(raw: string): string {