fix(acp): align prompt and workspace contracts

examples/acp-agent/README.md

@@ -21,15 +21,15 @@ Add to your Zed `settings.json` under `agent_servers`:
   "agent_servers": {
     "DeepSeek Harness": {
       "command": "pnpm",
-      "args": ["run", "demo:acp"],
+      "args": ["--dir", "/path/to/deepseek-harness", "run", "demo:acp"],
       "env": { "DEEPSEEK_API_KEY": "sk-…" }
     }
   }
 }
 ```
 
-The editor sets each session's `cwd` to the project it opens; the agent's bash tools run there (see the per-session `cwd` note in `packages/acp`), so the server does not need to be launched in the workspace.
+The editor sets each session's `cwd` to the project it opens; the agent's bash tools run there (see the per-session `cwd` note in `packages/acp`), so launch the server from the harness repo with `pnpm --dir …` and let ACP carry the workspace path per session.
 
 ## MVP limitations
 
-The bridge supports N concurrent sessions per connection, each in its own workspace `cwd` (RFC 011). Remaining limits: text-only prompts, `additionalDirectories` rejected (a session operates in its single `cwd`), and the tool-permission gate is deferred (`TODO(rfc010-permission-gate)` — tools run with the executor's full authority). See `packages/acp/README.md` for the full contract.
+The bridge supports N concurrent sessions per connection, each in its own workspace `cwd` (RFC 011). Remaining limits: prompts support ACP's baseline `text` and `resource_link` blocks only, `additionalDirectories` and `mcpServers` are rejected, and the tool-permission gate is deferred (`TODO(rfc010-permission-gate)` — tools run with the executor's full authority). See `packages/acp/README.md` for the full contract.

examples/acp-agent/start.ts

@@ -1,4 +1,4 @@
-import { pathToFileURL } from 'node:url'
+import { fileURLToPath, pathToFileURL } from 'node:url'
 import { Context } from 'cordis'
 import Loader from '@cordisjs/plugin-loader'
 
@@ -18,6 +18,8 @@ try {
   // ENOENT (no .env) is fine — rely on the ambient environment.
 }
 
+process.chdir(fileURLToPath(new URL('../..', import.meta.url)))
+
 const ctx = new Context()
 ctx.baseUrl = pathToFileURL(import.meta.dirname).href + '/'
 

examples/acp-agent/tests/acp.e2e.ts

@@ -27,11 +27,11 @@ import {
  */
 
 const startScript = fileURLToPath(new URL('../start.ts', import.meta.url))
-// Resolve tsx's loader to an ABSOLUTE path: the subprocess runs with cwd set to
-// a temp workdir (this test launches there and uses it as the session cwd; the
-// bridge no longer requires cwd === the launch dir, but a temp dir keeps the
-// test hermetic), where a bare `--import tsx` would not resolve from
-// node_modules. import.meta.resolve gives the worktree's tsx regardless of cwd.
+const repoRoot = fileURLToPath(new URL('../../../', import.meta.url))
+// Resolve tsx's loader to an ABSOLUTE path. The subprocess launches from the
+// harness repo (so pnpm/package resolution is stable) while each ACP session's
+// request cwd points at the temp workspace; import.meta.resolve gives the
+// worktree's tsx regardless of launch cwd.
 const tsxLoader = fileURLToPath(import.meta.resolve('tsx'))
 
 interface Spawned {
@@ -41,11 +41,11 @@ interface Spawned {
   stderr: string[]
 }
 
-function spawnAcpAgent(cwd: string): Spawned {
+function spawnAcpAgent(): Spawned {
   const child = spawn(
     process.execPath,
     ['--import', tsxLoader, startScript],
-    { cwd, env: { ...process.env }, stdio: ['pipe', 'pipe', 'pipe'] },
+    { cwd: repoRoot, env: { ...process.env }, stdio: ['pipe', 'pipe', 'pipe'] },
   )
   const stderr: string[] = []
   child.stderr.setEncoding('utf8')
@@ -91,13 +91,16 @@ describe('acp-agent stdout purity (no key required)', () => {
     // present at boot, not valid — the key is used only on a real model call,
     // which this purity test never triggers). So this runs WITHOUT real creds.
     const child = spawn(process.execPath, ['--import', tsxLoader, startScript], {
-      cwd: workdir,
+      cwd: repoRoot,
       env: { ...process.env, DEEPSEEK_API_KEY: process.env.DEEPSEEK_API_KEY ?? 'sk-dummy-for-boot' },
       stdio: ['pipe', 'pipe', 'pipe'],
     })
     const out: string[] = []
+    const stderr: string[] = []
     child.stdout.setEncoding('utf8')
+    child.stderr.setEncoding('utf8')
     child.stdout.on('data', (c: string) => out.push(c))
+    child.stderr.on('data', (c: string) => stderr.push(c))
 
     // Send a single initialize request as a newline-delimited JSON-RPC frame.
     const req = JSON.stringify({ jsonrpc: '2.0', id: 1, method: 'initialize', params: { protocolVersion: PROTOCOL_VERSION, clientCapabilities: {} } })
@@ -108,7 +111,7 @@ describe('acp-agent stdout purity (no key required)', () => {
     child.kill('SIGKILL')
 
     const lines = out.join('').split('\n').filter(l => l.trim().length > 0)
-    expect(lines.length).toBeGreaterThan(0)
+    expect(lines.length, stderr.join('')).toBeGreaterThan(0)
     for (const line of lines) {
       // Every stdout line MUST parse as JSON (a JSON-RPC frame). A non-JSON
       // line means a logger/print leaked onto the protocol channel.
@@ -120,7 +123,7 @@ describe('acp-agent stdout purity (no key required)', () => {
 describe.skipIf(!process.env.DEEPSEEK_API_KEY)('acp-agent e2e: real prompt over ACP', () => {
   it('runs a real turn and the agent writes the requested file (verified on disk)', async () => {
     workdir = await mkdtemp(join(tmpdir(), 'acp-e2e-'))
-    spawned = spawnAcpAgent(workdir)
+    spawned = spawnAcpAgent()
     const { client, updates } = spawned
 
     await client.initialize({ protocolVersion: PROTOCOL_VERSION, clientCapabilities: {} })