feat(ui): add dedicated TUI package

Move the interactive pi-tui front door into @deepseek-ai/dsh-tui while keeping @deepseek-ai/dsh-stdio line-oriented for pipes. Select the terminal package in the demo app, preserve logger ownership, and cover the production Loader composition with a PTY smoke test.

examples/coding-agent/tests/tui-keyless-smoke.e2e.ts

@@ -0,0 +1,101 @@
+import { spawn } from 'node:child_process'
+import { mkdtemp, rm } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { fileURLToPath } from 'node:url'
+import { describe, expect, it } from 'vitest'
+import { LOADER_SMOKE_TEST_TIMEOUT_MS } from '@deepseek-ai/dsh-loader-smoke'
+
+const binScript = fileURLToPath(new URL('../../../packages/examples/stdio-demo/src/bin.ts', import.meta.url))
+const configPath = fileURLToPath(new URL('../cordis.yml', import.meta.url))
+const tsconfigPath = fileURLToPath(new URL('../../../tsconfig.json', import.meta.url))
+const tsxLoader = fileURLToPath(import.meta.resolve('tsx'))
+
+const PTY_DRIVER = String.raw`
+import errno, os, pty, select, signal, sys, time
+node, tsx_loader, bin_script, config_path, tsconfig_path, cwd = sys.argv[1:]
+env = os.environ.copy()
+env.update({
+    "DEEPSEEK_API_KEY": "keyless-tui-no-call",
+    "DSH_HOME": os.path.join(cwd, ".dsh"),
+    "DSH_AGENTS_HOME": os.path.join(cwd, ".agents"),
+    "TSX_TSCONFIG_PATH": tsconfig_path,
+})
+pid, fd = pty.fork()
+if pid == 0:
+    os.chdir(cwd)
+    os.execvpe(node, [node, "--expose-internals", "--import", tsx_loader, bin_script, config_path], env)
+
+output = bytearray()
+sent_exit = False
+deadline = time.monotonic() + 25
+status = None
+while time.monotonic() < deadline:
+    ready, _, _ = select.select([fd], [], [], 0.05)
+    if ready:
+        try:
+            chunk = os.read(fd, 65536)
+        except OSError as error:
+            if error.errno != errno.EIO:
+                raise
+            chunk = b""
+        if chunk:
+            output.extend(chunk)
+    if not sent_exit and b"agent REPL ready." in output:
+        os.write(fd, b"/exit\r")
+        sent_exit = True
+    waited, candidate = os.waitpid(pid, os.WNOHANG)
+    if waited == pid:
+        status = candidate
+        break
+
+if status is None:
+    os.kill(pid, signal.SIGKILL)
+    _, status = os.waitpid(pid, 0)
+sys.stdout.buffer.write(output)
+if not sent_exit:
+    sys.stderr.write("TUI did not render its welcome marker before timeout\n")
+    sys.exit(124)
+if not os.WIFEXITED(status) or os.WEXITSTATUS(status) != 0:
+    sys.stderr.write("TUI child did not exit cleanly\n")
+    sys.exit(125)
+`
+
+async function runTuiLoaderSmoke(): Promise<string> {
+  const cwd = await mkdtemp(join(tmpdir(), 'coding-tui-smoke-'))
+  try {
+    return await new Promise((resolve, reject) => {
+      const child = spawn('python3', [
+        '-c',
+        PTY_DRIVER,
+        process.execPath,
+        tsxLoader,
+        binScript,
+        configPath,
+        tsconfigPath,
+        cwd,
+      ], { stdio: ['ignore', 'pipe', 'pipe'] })
+      let stdout = ''
+      let stderr = ''
+      child.stdout.setEncoding('utf8')
+      child.stdout.on('data', (chunk: string) => { stdout += chunk })
+      child.stderr.setEncoding('utf8')
+      child.stderr.on('data', (chunk: string) => { stderr += chunk })
+      child.once('error', reject)
+      child.once('exit', (code) => {
+        if (code === 0) resolve(stdout)
+        else reject(new Error(`TUI PTY smoke exited ${String(code)}. stdout:\n${stdout}\nstderr:\n${stderr}`))
+      })
+    })
+  } finally {
+    await rm(cwd, { recursive: true, force: true })
+  }
+}
+
+describe('coding-agent TUI keyless smoke (real Loader tree in a PTY)', () => {
+  it('boots pi-tui, renders the configured banner, accepts /exit, and restores the terminal', async () => {
+    const output = await runTuiLoaderSmoke()
+    expect(output).toContain('DEEPSEEK')
+    expect(output).toContain('agent REPL ready.')
+  }, LOADER_SMOKE_TEST_TIMEOUT_MS)
+})