docs: add example for Gemini model

examples/08-gemini-test.ts

@@ -0,0 +1,49 @@
+/**
+ * Quick smoke test for the Copilot adapter.
+ *
+ * Run:
+ *   npx tsx examples/05-copilot-test.ts
+ *
+ * If GITHUB_COPILOT_TOKEN is not set, the adapter will start an interactive
+ * OAuth2 device flow — you'll be prompted to sign in via your browser.
+ */
+
+import { OpenMultiAgent } from '../src/index.js'
+import type { OrchestratorEvent } from '../src/types.js'
+
+const orchestrator = new OpenMultiAgent({
+  defaultModel: 'gemini-2.5-flash',
+  defaultProvider: 'gemini',
+  onProgress: (event: OrchestratorEvent) => {
+    if (event.type === 'agent_start') {
+      console.log(`[start]    agent=${event.agent}`)
+    } else if (event.type === 'agent_complete') {
+      console.log(`[complete] agent=${event.agent}`)
+    }
+  },
+})
+
+console.log('Testing Gemini adapter with gemini-2.5-flash...\n')
+
+const result = await orchestrator.runAgent(
+  {
+    name: 'assistant',
+    model: 'gemini-2.5-flash',
+    provider: 'gemini',
+    systemPrompt: 'You are a helpful assistant. Keep answers brief.',
+    maxTurns: 1,
+    maxTokens: 256,
+  },
+  'What is 2 + 2? Reply in one sentence.',
+)
+
+if (result.success) {
+  console.log('\nAgent output:')
+  console.log('─'.repeat(60))
+  console.log(result.output)
+  console.log('─'.repeat(60))
+  console.log(`\nTokens: input=${result.tokenUsage.input_tokens}, output=${result.tokenUsage.output_tokens}`)
+} else {
+  console.error('Agent failed:', result.output)
+  process.exit(1)
+}