fix(groq): strip unsupported store field (#983)

docs/advanced-setup.md

@@ -159,11 +159,13 @@ export OPENAI_MODEL=meta-llama/Llama-3.3-70B-Instruct-Turbo
 
 ```bash
 export CLAUDE_CODE_USE_OPENAI=1
-export OPENAI_API_KEY=gsk_...
+export GROQ_API_KEY=gsk_...
 export OPENAI_BASE_URL=https://api.groq.com/openai/v1
 export OPENAI_MODEL=llama-3.3-70b-versatile
 ```
 
+`GROQ_API_KEY` matches the built-in Groq gateway preset. `OPENAI_API_KEY` also works as a fallback on the generic OpenAI-compatible path, but `GROQ_API_KEY` is the preferred variable for Groq-specific setup.
+
 ### Mistral
 
 ```bash

src/integrations/gateways/groq.ts

@@ -16,6 +16,7 @@ export default defineGateway({
     kind: 'openai-compatible',
     openaiShim: {
       supportsAuthHeaders: true,
+      removeBodyFields: ['store'],
     },
   },
   preset: {

src/services/api/openaiShim.test.ts

@@ -4098,6 +4098,40 @@ test('Moonshot: uses max_tokens (not max_completion_tokens) and strips store', a
   expect(requestBody?.store).toBeUndefined()
 })
 
+test('Groq: keeps max_completion_tokens and strips unsupported store', async () => {
+  process.env.OPENAI_BASE_URL = 'https://api.groq.com/openai/v1'
+  process.env.OPENAI_API_KEY = 'gsk-test'
+
+  let requestBody: Record<string, unknown> | undefined
+  globalThis.fetch = (async (_input, init) => {
+    requestBody = JSON.parse(String(init?.body))
+    return new Response(
+      JSON.stringify({
+        id: 'chatcmpl-1',
+        model: 'llama-3.3-70b-versatile',
+        choices: [
+          { message: { role: 'assistant', content: 'ok' }, finish_reason: 'stop' },
+        ],
+        usage: { prompt_tokens: 3, completion_tokens: 1, total_tokens: 4 },
+      }),
+      { headers: { 'Content-Type': 'application/json' } },
+    )
+  }) as FetchType
+
+  const client = createOpenAIShimClient({}) as OpenAIShimClient
+  await client.beta.messages.create({
+    model: 'llama-3.3-70b-versatile',
+    system: 'you are groq',
+    messages: [{ role: 'user', content: 'hi' }],
+    max_tokens: 256,
+    stream: false,
+  })
+
+  expect(requestBody?.max_completion_tokens).toBe(256)
+  expect(requestBody?.max_tokens).toBeUndefined()
+  expect(requestBody?.store).toBeUndefined()
+})
+
 test('Moonshot: echoes reasoning_content on assistant tool-call messages', async () => {
   // Regression for: "API Error: 400 {"error":{"message":"thinking is enabled
   // but reasoning_content is missing in assistant tool call message at index