fix(sandbox): ignore generated output and clean failed drafts

scripts/sandbox-workspace-regression.ts

@@ -27,6 +27,10 @@ if (process.platform !== 'win32') throw new Error('Persistent workspace requires
 await fs.mkdir(resolve('.tmp'), { recursive: true })
 const fixture = await fs.mkdtemp(resolve('.tmp/sandbox-workspace-')), workspace = join(fixture, 'project \u4e2d\u6587 ^'), stateRoot = join(fixture, 'state')
 await fs.mkdir(workspace); await fs.writeFile(join(workspace, 'file.txt'), 'host-before')
+for (const generated of ['out', 'dist', 'release']) {
+  await fs.mkdir(join(workspace, generated), { recursive: true })
+  await fs.writeFile(join(workspace, generated, 'generated.bin'), 'generated-output')
+}
 configureSandbox({ stateRoot, resourceDirectory: resolve('resources/sandbox/win32-x64') })
 let approvals = 0
 const context = { workspaceRoot: workspace, sessionId: 'persistent-session', runId: 'persistent-run', toolCallId: 'persistent-call', approve: async () => { approvals++; return true } }
@@ -42,6 +46,7 @@ try {
   let result = await run('echo draft-value>file.txt')
   check('successful command saves a draft without host writes or approval', result.ok && result.data.writeback === 'deferred' && approvals === 0 && await fs.readFile(join(workspace, 'file.txt'), 'utf8') === 'host-before')
   const first = await revision()
+  check('generated build output stays outside the retained draft', !first.tree.some(entry => /^(out|dist|release)(\/|$)/.test(entry.path)) && first.excluded >= 3)
   result = await run('type file.txt')
   const second = await revision()
   check('next real native command reads the retained draft', result.ok && result.data.stdout.includes('draft-value') && result.data.workspace?.changes.length === 1)