fix(worker): keep-id compat, zombie tmux clients, nvm in box image

- Box init + chownInBox exec explicitly as root: under podman keep-id the
  container's default user is the mapped uid, which cannot useradd/chown.
- Init renames an existing uid-1000 passwd entry (podman keep-id injects one
  named after the HOST user) instead of adding a duplicate that would win the
  getpwuid lookup and make whoami report the wrong name.
- Terminal connections tag their shell with a per-connection marker and reap
  the process group on WebSocket close: closing the attach socket never
  killed the exec'd shell, so every disconnect leaked an attached tmux client
  (session stuck at the smallest zombie's size; enough dead clients starve
  tmux rendering for live ones).
- Job image: nvm 0.39.5 at /usr/local/nvm (user-writable) with
  /etc/profile.d/nvm.sh, matching what user dotfiles expect; docs for the box
  user + ownership model.

apps/agent-worker/src/box-init.ts

@@ -27,6 +27,9 @@ const execRoot = async (
     redact,
     timeoutMs: 120_000,
     input,
+    // Explicit: under podman keep-id the container's DEFAULT user is the
+    // mapped uid (1000), not root, and useradd/chpasswd/sudoers need root.
+    user: 'root',
   });
   if (result.exitCode !== 0) {
     throw new Error(`Box ${label} failed: ${result.output}`);

apps/agent-worker/src/runtime/box-user.ts

@@ -18,11 +18,15 @@ export const linuxUsername = (spoonUsername: string): string => {
   return /^[a-z_]/.test(cleaned) ? cleaned : `u${cleaned}`.slice(0, 32);
 };
 
-// Idempotent root init: create the user at the (already mounted) home, grant
-// wheel, and chown the home ONCE (marker-guarded — later host-side writes are
-// repaired by targeted chowns, so a big home is never re-walked). `-o` allows
-// the uid even if the image ever gains a uid-1000 user; `-M` skips skeleton
-// copy since the mounted home persists across containers.
+// Idempotent root init: ensure a SINGLE uid-1000 passwd entry with our name,
+// grant wheel, and chown the home ONCE (marker-guarded — later host-side
+// writes are repaired by targeted chowns, so a big home is never re-walked).
+//
+// The uid-1000 entry may already exist: podman --userns=keep-id injects one
+// named after the HOST user. A second entry at the same uid would win the
+// getpwuid lookup (whoami would report the host username), so an existing
+// entry is RENAMED rather than duplicated. `-M` skips skeleton copy since the
+// mounted home persists across containers.
 export const buildBoxInitScript = (args: {
   username: string;
   home: string;
@@ -32,7 +36,10 @@ export const buildBoxInitScript = (args: {
   const marker = shellQuote(`${args.home}/.spoon/chown-v1`);
   return [
     'set -e',
-    `if ! id -u ${user} >/dev/null 2>&1; then`,
+    `existing="$(getent passwd ${BOX_UID} | cut -d: -f1 || true)"`,
+    `if [ -n "$existing" ] && [ "$existing" != ${user} ]; then`,
+    `  usermod -l ${user} -d ${home} -s /bin/bash "$existing"`,
+    `elif [ -z "$existing" ]; then`,
     `  useradd -u ${BOX_UID} -o -M -d ${home} -s /bin/bash ${user}`,
     'fi',
     `usermod -aG wheel ${user}`,

apps/agent-worker/src/runtime/docker.ts

@@ -445,6 +445,10 @@ export const chownInBox = async (args: {
     containerRuntime(),
     [
       'exec',
+      // Explicit root: under podman keep-id the container default user is the
+      // mapped uid, which cannot chown files it does not own.
+      '-u',
+      'root',
       args.containerName,
       'chown',
       '-R',

apps/agent-worker/src/terminal.ts

@@ -1,3 +1,4 @@
+import { randomUUID } from 'node:crypto';
 import type { Server } from 'node:http';
 import type { Duplex } from 'node:stream';
 import type { WebSocket } from 'ws';
@@ -7,7 +8,11 @@ import type { BoxHandle } from './user-container';
 import { boxHomePaths } from './box';
 import { env } from './env';
 import { linuxUsername } from './runtime/box-user';
-import { chownInBox, getDockerClient } from './runtime/docker';
+import {
+  chownInBox,
+  getDockerClient,
+  killBoxProcessesByMarker,
+} from './runtime/docker';
 import { openExecStream } from './runtime/exec-stream';
 import {
   parseBoxTokenUsername,
@@ -53,10 +58,19 @@ const closeWithReason = (ws: WebSocket, code: number, reason: string) => {
 
 // The login-shell command shared by the job and box terminals: prefer a
 // resumable tmux session, else fall back to a plain interactive login shell.
-const SHELL_CMD = [
+//
+// The marker comment keeps a per-connection tag in the wrapper bash's argv so
+// the bridge can kill THIS connection's process group when the WebSocket
+// closes. Without it, every disconnect leaks an attached tmux client (the
+// exec process survives the closed attach socket); the session then stays
+// sized to the smallest zombie client, and once enough dead clients' ptys
+// fill up, tmux stops rendering for live ones entirely. tmux/bash must NOT be
+// exec'd — that would replace the marker-carrying argv.
+export const buildTerminalShellCommand = (marker: string): string[] => [
   '/bin/bash',
   '-lc',
-  'if command -v tmux >/dev/null 2>&1; then exec tmux new-session -A -s spoon; else exec bash -il; fi',
+  `# ${marker}
+if command -v tmux >/dev/null 2>&1; then tmux new-session -A -s spoon; else bash -il; fi`,
 ];
 
 type ShellBridgeOptions = {
@@ -107,6 +121,7 @@ const runShellBridge = async (ws: WebSocket, opts: ShellBridgeOptions) => {
     else pendingInput.push(data);
   });
 
+  const marker = `spoon-term-${randomUUID()}`;
   const handleHolder: { current?: BoxHandle } = {};
   let released = false;
   // Read through a function so TS doesn't narrow `released` to a constant — the
@@ -117,6 +132,15 @@ const runShellBridge = async (ws: WebSocket, opts: ShellBridgeOptions) => {
     released = true;
     execHolder.current?.stream.end();
     execHolder.current?.stream.destroy();
+    // Closing the attach socket does NOT kill the exec'd shell — reap this
+    // connection's process group so dead tmux clients don't accumulate. The
+    // tmux server daemonized into its own group and survives.
+    const boxName = handleHolder.current?.boxName;
+    if (boxName && execHolder.current) {
+      void killBoxProcessesByMarker({ containerName: boxName, marker }).catch(
+        () => undefined,
+      );
+    }
     handleHolder.current?.release();
   };
   ws.on('close', cleanup);
@@ -166,7 +190,7 @@ const runShellBridge = async (ws: WebSocket, opts: ShellBridgeOptions) => {
       AttachStderr: true,
       Tty: true,
       User: opts.user,
-      Cmd: SHELL_CMD,
+      Cmd: buildTerminalShellCommand(marker),
       Env: ['TERM=xterm-256color', ...opts.envFlags],
       WorkingDir: opts.cwd,
     });

apps/agent-worker/tests/unit/box-user.test.ts

@@ -31,8 +31,14 @@ describe('buildBoxInitScript', () => {
     username: 'gabriel',
     home: '/home/Gabriel',
   });
-  it('creates the user idempotently with uid 1000 at the given home', () => {
-    expect(script).toContain("id -u 'gabriel'");
+  it('renames an existing uid-1000 entry instead of duplicating it', () => {
+    // podman --userns=keep-id injects a passwd entry named after the HOST user
+    // at the mapped uid; a second uid-1000 entry would win the getpwuid lookup
+    // and make whoami report the host username.
+    expect(script).toContain('getent passwd 1000');
+    expect(script).toContain("usermod -l 'gabriel'");
+  });
+  it('creates the user with uid 1000 at the given home when none exists', () => {
     expect(script).toContain('useradd');
     expect(script).toContain('-u 1000');
     expect(script).toContain("-d '/home/Gabriel'");

apps/agent-worker/tests/unit/terminal-resize.test.ts

@@ -44,3 +44,18 @@ describe('parseResizeMessage', () => {
     expect(parseResizeMessage(msg, false)).toEqual({ cols: 1000, rows: 1 });
   });
 });
+
+describe('buildTerminalShellCommand', () => {
+  test('embeds the connection marker without exec-ing the shell away', async () => {
+    const { buildTerminalShellCommand } = await load();
+    const command = buildTerminalShellCommand('spoon-term-abc-123');
+    expect(command[0]).toBe('/bin/bash');
+    const script = command[2] ?? '';
+    // Marker must stay in the wrapper's argv for pgrep-based cleanup, so the
+    // inner shell/tmux must NOT be exec'd (exec would replace the argv).
+    expect(script).toContain('# spoon-term-abc-123');
+    expect(script).not.toContain('exec tmux');
+    expect(script).not.toContain('exec bash');
+    expect(script).toContain('tmux new-session -A -s spoon');
+  });
+});