always run pi as the service user, drop the sudo -u branch

- the sandbox already drops privileges to the OS user (id -un), so pi-bridge was
  the only code path that switched to a per-user unix account
- the four accounts it targeted (andrepadez, john-wick, fedra, miguelbenoliel)
  are vestigial: created by scripts/provision-existing-users.sh, with no home
  dirs, no files, no processes. the only live account is pastilhas@officer.dev,
  which maps to the service user, so isServiceUser was always true and the
  sudo -u branch could never fire
- add TODO.md tracking the leftover username plumbing, the useradd script, known
  bugs (task-executor relative cwd, bootstrap pi EEXIST), and the ufw 9010 rule

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

TODO.md

@@ -0,0 +1,53 @@
+# TODO
+
+Deferred work. Context: Officer is collapsing from multi-tenant / open-source-ready to a
+**single-user platform**. Treat multi-tenant indirection as accidental complexity, not a requirement.
+
+## Single-user cleanup
+
+- [ ] **Remove dead `username` plumbing.** `pi-bridge.spawnPi` no longer uses `username` — it always
+      runs as the service user. But the handlers still compute `toShellUsername(...)` and thread it
+      through `sendAndAwait` → `spawnOptions`, where nothing reads it. `send-claude-code` declares
+      `username` (lines 8, 36) without using it. Typechecks clean today (excess-property checks don't
+      fire on variables), so it silently *looks* load-bearing.
+      Touches: `channels/{whatsapp,telegram,discord}/handler.ts`, `channels/send-and-await.ts`,
+      `channels/send-claude-code.ts`. After this, `toShellUsername` has one caller left
+      (`provision.ts` → `generateClaudeSettings`) and may be inlinable.
+
+- [ ] **Delete or gut `scripts/provision-existing-users.sh`.** Line ~100 runs
+      `sudo useradd -d "$HOME_DIR" -s /bin/zsh -M "$shell_user"`. This is what created the four
+      vestigial Unix accounts (`andrepadez`, `john-wick`, `fedra`, `miguelbenoliel`) that cluttered
+      the lightdm greeter. Nothing in the server creates Unix users; if this script runs again they
+      come back.
+
+- [ ] **Collapse the rest of the multi-tenant machinery.** Candidates, in rough order of payoff:
+      roles (`Super Admin`/`Member`), the sandboxed-vs-unsandboxed path split, per-email home dirs
+      under `dev-data/{email}/home`, per-user server state (dock, user apps, AppRegistry keyed by
+      email), and auth (passkeys-per-origin, JWT signin, unmounted `PasskeyGate`).
+
+## Known bugs
+
+- [ ] **Convert Audio task fails with `ENOENT: posix_spawn 'bash'`.** Misleading error — the real
+      cause is a *relative* `cwd` passed to `Bun.spawn` (ENOENT fires when the child's cwd doesn't
+      exist, not when the binary is missing). Fix is in `api/tasks/task-executor.ts`: resolve
+      `msg.cwd` against the user's home when it isn't absolute
+      (`isAbsolute(msg.cwd) ? msg.cwd : join(homeDir, msg.cwd)`). Was written and verified once, then
+      discarded in a working-tree cleanup.
+
+- [ ] **`bootstrap.ts` runs `npm install -g` for Pi on every boot.** `findPiPackageDir` checks stale
+      paths and an outdated package name, so `installPi` always fires and floods the logs with
+      `EEXIST` noise. Should detect `@earendil-works/pi-coding-agent` at the real npm prefix.
+
+## Infra (alpha)
+
+- [ ] **`ufw` blocks port 9010 on the LAN.** Default deny incoming; only `22/tcp`, `80/tcp`,
+      `443/tcp`, and everything on `tailscale0` are allowed — so `http://192.168.47.196:9010` is
+      unreachable from the LAN while localhost and Tailscale work.
+      Fix: `sudo ufw allow from 192.168.47.0/24 to any port 9010 proto tcp`
+
+## Backburner
+
+- [ ] **Music tagging feature** (`/music`, Mp3tag-inspired). v1 was scoped as a two-panel workspace —
+      file browser left, table right, single "Load" context-menu item flattening audio files into the
+      table. Discarded before completion; would need `GET /file-browser/flatten-audio`, a
+      `useFilesAPI.flattenAudio` method, and the Music app panel rebuilt from scratch.

src/servers/api/pi/pi-bridge.ts

@@ -12,7 +12,6 @@ import {
   getUserExtensionsDir,
   getGlobalToolsDir,
   getUserToolsDir,
-  toShellUsername,
 } from '../../data-path';
 import { logger } from './logger';
 
@@ -84,7 +83,6 @@ async function resolveApiKeyForModel(model: string): Promise<string | null> {
 
 type SpawnPiOptions = {
   sessionFile?: string;
-  username?: string;
   role?: string;
 };
 
@@ -121,43 +119,27 @@ export async function spawnPi(
 
   const homeDir = getHomeDirForRole(email, options?.role ?? null);
   const toolsDirs = [getGlobalToolsDir(), getUserToolsDir(email)].join(':');
-  const shellUsername = options?.username ?? toShellUsername('', email);
-
-  const isServiceUser = (options?.username ?? toShellUsername('', email)) === (process.env.USER ?? '');
 
   const env: Record<string, string> = {
-    HOME: homeDir,
+    HOME: process.env.HOME ?? '',
     OFFICER_USER_HOME: homeDir,
     OFFICER_USER_ROOT: join(DATA_PATH, email),
-    PI_CODING_AGENT_DIR: isServiceUser ? PI_CONFIG_DIR : join(homeDir, '.pi', 'agent'),
+    PI_CODING_AGENT_DIR: PI_CONFIG_DIR,
     PI_TOOLS_DIRS: toolsDirs,
     OFFICER_EMAIL_DB: join(DATA_PATH, email, 'emails.db'),
     TERM: 'xterm-256color',
     PATH: process.env.PATH ?? '',
   };
 
-  // For service user, keep real HOME so Pi finds its config
-  if (isServiceUser) {
-    env.HOME = process.env.HOME ?? '';
-  }
+  const proc = Bun.spawn(piArgs, {
+    cwd,
+    stdin: 'pipe',
+    stdout: 'pipe',
+    stderr: 'pipe',
+    env: { ...process.env, ...env },
+  });
 
-  const proc = isServiceUser
-    ? Bun.spawn(piArgs, {
-        cwd,
-        stdin: 'pipe',
-        stdout: 'pipe',
-        stderr: 'pipe',
-        env: { ...process.env, ...env },
-      })
-    : Bun.spawn(['sudo', '-u', shellUsername, 'env', ...Object.entries(env).map(([k, v]) => `${k}=${v}`), ...piArgs], {
-        cwd,
-        stdin: 'pipe',
-        stdout: 'pipe',
-        stderr: 'pipe',
-      });
-
-  logger.info('Spawned Pi as user', {
-    username: shellUsername,
+  logger.info('Spawned Pi', {
     model,
     skills: skillFlags.filter((f) => f !== '--skill').length,
     extensions: extensionFlags.filter((f) => f !== '--extension').length,