chore: import upstream snapshot with attribution

test/python/performance.bench.ts

@@ -0,0 +1,51 @@
+import fs from 'fs';
+import os from 'os';
+import path from 'path';
+
+import { describe, expect, it } from 'vitest';
+import { PythonProvider } from '../../src/providers/pythonCompletion';
+
+describe('Performance Benchmarks (manual)', () => {
+  function writeTempPython(content: string): string {
+    const tempFile = path.join(os.tmpdir(), `bench-${Date.now()}.py`);
+    fs.writeFileSync(tempFile, content);
+    return tempFile;
+  }
+
+  it('benchmark: heavy import speedup', async () => {
+    const scriptPath = writeTempPython(`
+import time
+time.sleep(1)  # Simulate 1s import
+
+def call_api(prompt, options, context):
+    return {"output": "test"}
+`);
+
+    const provider = new PythonProvider(`file://${scriptPath}`, {
+      config: { basePath: process.cwd() },
+    });
+
+    const start = Date.now();
+    await provider.initialize();
+    const initTime = Date.now() - start;
+
+    console.log(`Initialization (1 worker): ${initTime}ms`);
+
+    const callStart = Date.now();
+    for (let i = 0; i < 10; i++) {
+      await provider.callApi(`test ${i}`);
+    }
+    const totalCallTime = Date.now() - callStart;
+    const avgCallTime = totalCallTime / 10;
+
+    console.log(`10 calls total: ${totalCallTime}ms`);
+    console.log(`Avg per call: ${avgCallTime}ms`);
+    console.log(`Expected without persistence: ~10,000ms (1s import × 10 calls)`);
+    console.log(`Speedup: ${(10000 / totalCallTime).toFixed(1)}x`);
+
+    expect(avgCallTime).toBeLessThan(100); // Each call should be fast
+
+    await provider.shutdown();
+    fs.unlinkSync(scriptPath);
+  }, 30000);
+});