Models stage-d (default) + stage-e (next-edit companion); extension 0.6.1

- stage-d: next-line / block-close / multi-line fixes, symbols format 2, TS errors in the header.
  Held-out: 0.426 exact / 0.700 edit sim (stage-c 0.405 / 0.689); block close 0.27 -> 0.79.
- stage-e: next-edit (80% exact region rewrites, abstains on 100% of no-edit samples).
- Manifest: nextEditModel (companion) and nextEditFormat (older extensions ignore it, so they
  never use next-edit with the empty-output deletion bug).
- Daemon: next-edit served by the companion model in a second llama-server, started after the
  main model loads.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J39imRDT8L7xYbWzsVWd8A

extensions/vscode/test/managed.e2e.mjs

@@ -36,20 +36,29 @@ const step = (name, fn) => fn().then(r => { console.log(`PASS  ${name}`); return
 
 // 1. Simulate an interrupted model download: first 100 MB already on disk.
 fs.mkdirSync(path.join(storage, 'models'), { recursive: true })
-const modelSrc = path.join(releaseDir, 'stage-c-q8_0.gguf')
+const modelSrc = path.join(releaseDir, 'stage-d-q8_0.gguf')
 const fd = fs.openSync(modelSrc, 'r'); const buf = Buffer.alloc(100e6); fs.readSync(fd, buf, 0, buf.length, 0); fs.closeSync(fd)
-fs.writeFileSync(path.join(storage, 'models', 'stage-c-q8_0.gguf.part'), buf)
+fs.writeFileSync(path.join(storage, 'models', 'stage-d-q8_0.gguf.part'), buf)
 
 let t0 = Date.now()
 const prepared = await step('first run: manifest, resumed + verified model download, llama.cpp download + unpack', () => core.prepare(storage, daemonDir, '0.4.0-test', settings, progress))
-console.log(`      ${((Date.now() - t0) / 1000).toFixed(1)} s; range requests: ${rangeRequests}; model verified: ${fs.existsSync(path.join(storage, 'models', 'stage-c-q8_0.gguf.verified'))}`)
+console.log(`      ${((Date.now() - t0) / 1000).toFixed(1)} s; range requests: ${rangeRequests}; model verified: ${fs.existsSync(path.join(storage, 'models', 'stage-d-q8_0.gguf.verified'))}`)
 assert.ok(rangeRequests >= 1, 'download should have resumed with a Range request')
 const cfg = JSON.parse(fs.readFileSync(prepared.configPath, 'utf8'))
 assert.ok(fs.existsSync(cfg.llamaServer.binary), 'llama-server unpacked')
+await step('next-edit companion downloaded and wired (stage-d → stage-e)', async () => {
+  assert.equal(cfg.defaultModel, 'stage-d')
+  assert.equal(cfg.models['stage-d'].nextEditModel, 'stage-e')
+  assert.equal(cfg.models['stage-e'].nextEdit, true)
+  assert.ok(fs.existsSync(path.join(storage, 'models', 'stage-e-q8_0.gguf.verified')))
+})
 
 await step('daemon starts on the editor runtime', async () => assert.equal(await core.ensureRunning(storage, daemonDir, prepared, settings.port, progress), 'started'))
 const fim = await (await fetch('http://127.0.0.1:7111/v1/fim', { method: 'POST', body: JSON.stringify({ repo: 'e2e', path: 'src/a.ts', prefix: "import { z } from 'zod'\nexport const s = z.object({ a: z.string() })\nexport type S = ", suffix: '\n' }) })).json()
 await step(`completion through the managed daemon (${JSON.stringify(fim.text)})`, async () => assert.match(fim.text, /z\.infer<typeof s>/))
+const neText = "export function f(s: string) {\n  const t = s.trim()\n  return parse(t))\n}\n"
+const ne = await (await fetch('http://127.0.0.1:7111/v1/next-edit', { method: 'POST', body: JSON.stringify({ repo: 'e2e', path: 'src/f.ts', text: neText, cursor: neText.indexOf('(t)') + 1 }) })).json()
+await step(`next-edit through the companion model (${JSON.stringify(ne.newText ?? ne.error ?? ne)})`, async () => assert.ok(ne.newText?.includes('return parse(t)\n')))
 
 t0 = Date.now()
 const again = await step('second window: no re-download, daemon reused', async () => {