feat(cli): codeman web -d and codeman service install (#231)

Two ways to keep the server running, split by how long it should last.

`codeman web -d` relaunches the same entry script detached (setsid), with
`--stop` and `--status` alongside it. A pidfile and log live in the data
dir. `nohup` is not what makes this work: Node re-arms SIGHUP to its
default disposition even when it inherits "ignore", and cli.ts handles
SIGHUP with a graceful shutdown, so a delivered HUP still stops the
server. Removing the shell's ability to send one is the fix.

`codeman service install|uninstall|status` writes and loads the systemd
user unit or the LaunchAgent, with the installing shell's PATH baked in
(launchd hands a job /usr/bin:/bin:/usr/sbin:/sbin, which finds neither a
Homebrew/nvm node nor tmux/claude). install.sh already covers one-liner
installs; this is for npm globals.

Both refuse to start when a server is already up on the data dir, since a
second instance on the shared tmux socket attaches PTYs to the first
one's live sessions. Both poll /api/status until the child answers or
dies rather than reporting a success they have not seen. `--stop` checks
the pid still looks like a Codeman server before signalling it.

The systemd unit name and launchd label move to config/service-names.ts
so install.sh, detectSupervisor() and service install cannot drift into
supervising two copies. Instance-scoped, unchanged for the default
instance.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -109,6 +109,8 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 | CI-equivalent test sweep       | `npm run test:ci` (full suite minus browser/perf — see Testing)                                                                                                                                                |
 | Production start               | `npm run start`                                                                                                                                                                                                |
 | Production logs                | `journalctl --user -u codeman-web -f`                                                                                                                                                                          |
+| Detached server                | `codeman web -d` (`--status`, `--stop`; pidfile+log at `dataPath('web.pid'/'web.log')`). ⚠ Refuses to start a 2nd server on one data dir — see Instance isolation                                              |
+| Install/remove the service     | `codeman service install` / `status` / `uninstall` (systemd user unit on Linux, LaunchAgent on macOS; names from `config/service-names.ts`)                                                                     |
 
 **CI**: `.github/workflows/ci.yml` (push to master/main + PRs, Node 22) runs two jobs: **(1)** `check:lockfile`, `typecheck`, `lint`, `check:frontend-syntax`, `format:check`, then a **server boot smoke test** (`tsx src/index.ts web --port 3151` must answer `/api/status` within 30s); **(2)** the **unit/integration test suite** via `npm run test:ci` (`config/vitest.ci.config.ts` — excludes the browser-driven `test/mobile/**` suite, `perf-*` benchmarks, and 3 Playwright tests). Tests are tmux-safe in CI: `TmuxManager` no-ops all shell commands under `VITEST` (see Testing).
 
@@ -141,7 +143,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 
 | Domain           | Key files                                                                                              | Notes                                                                                            |
 | ---------------- | -------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------- |
-| **Entry**        | `src/index.ts`, `src/cli.ts`                                                                           |                                                                                                  |
+| **Entry**        | `src/index.ts`, `src/cli.ts`, `daemon-control`, `service-installer`, `config/service-names`             | The last three back `web -d` / `service install`                                                 |
 | **Session**      | `src/session.ts` ★, `session-manager`, `session-auto-ops`, `session-cli-builder`, `session-task-cache`, `session-order` (pure), `session-pty-exit-breaker`, `usage-limit-patterns`, `usage-telemetry`; `src/services/unified-session-service.ts` | Pure/unit-tested helpers are split out of `session.ts` on purpose                                 |
 | **Mux**          | `src/mux-interface.ts`, `src/mux-factory.ts`, `src/tmux-manager.ts` ★                                  |                                                                                                  |
 | **Respawn**      | `src/respawn-controller.ts` ★ + 4 helpers (`-adaptive-timing`, `-health`, `-metrics`, `-patterns`)      | Read `docs/respawn-state-machine.md` first                                                       |
@@ -212,6 +214,8 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 
 **Terminal scrollback strip + wheel/touch forwarding** (#205): codex/claude/gemini get the FULL strip (alt-screen, `3J`, mouse DECSETs); tmux-backed shell/opencode/antigravity get a NARROW strip (alt-screen toggles only — it removes tmux's own attach-time `smcup`, which otherwise parks xterm in the scrollback-less alt buffer and turns the wheel into arrow keys). ⚠️ Gated on `useMux`: direct-PTY fallback sessions must keep the alt screen for vim/less/htop. Wheel AND touch forward to the CLI transcript for codex/claude ≥ 2.1.187 at ANY scroll position (snap-to-bottom first); Shift+wheel and the `terminalWheelLocalScrollback` setting stay local. `_wheelScrollLines()` reads `ev.deltaMode` (Firefox = LINE units). ⚠️ When that gate is FALSE on a claude session whose local buffer is hollow (`baseY === 0`), the gesture becomes coalesced PageUp/PageDown key sends (`_maybePageCliTranscript`) instead of a no-op; ⚠️ and `getClaudeCliVersion()` must never cache a FAILED probe (one timeout used to disable forwarding process-wide until restart). `_logScrollRouting()` prints the routing decision and its inputs once per session — read it before diagnosing a scroll report. → [architecture-invariants#terminal-scrollback-strip-flavors-and-wheeltouch-forwarding](docs/architecture-invariants.md#terminal-scrollback-strip-flavors-and-wheeltouch-forwarding)
 
+**Detached start + service install** (issue #231): `codeman web -d` relaunches the SAME entry script with `detached:true` (setsid), so there is no controlling terminal and no shell job entry. ⚠️ `nohup` is NOT what makes this work: Node re-arms SIGHUP to its default disposition even when it inherits "ignore", and `cli.ts` handles SIGHUP with a graceful shutdown, so a delivered HUP still stops the server. ⚠️ Both `-d` and `service install` must REFUSE when a server is already up on this data dir (pidfile check + `/api/status` probe): a second instance on the shared tmux socket attaches PTYs to the first one's live sessions. ⚠️ Neither may report success it has not observed — the parent polls `/api/status` until the child answers or dies, since `launchctl load` and a clean spawn are both silent about a server that starts and immediately exits. `--stop` verifies the pid still LOOKS like a Codeman server (`ps -o command=`) before signalling, because pids get recycled. Unit/label names live in `config/service-names.ts` so install.sh, `detectSupervisor()` and `service install` cannot drift into supervising two copies; they are instance-scoped, and identical to the historical names for the default instance. `service install` bakes the installing shell's PATH into the unit (launchd gives a job `/usr/bin:/bin:/usr/sbin:/sbin`, which finds neither a Homebrew/nvm `node` nor `tmux`/`claude`) and never writes `CODEMAN_PASSWORD` into it. → [architecture-invariants#detached-start-and-service-install](docs/architecture-invariants.md#detached-start-and-service-install)
+
 **Self-update** (App Settings → Updates): in-app updater for git-clone installs supervised by systemd/launchd (`systemd`, `launchd`, `launchd-daemon`, else `none` → "restart manually"). The update restarts the very process running it, so the real work runs in a DETACHED `scripts/self-update.sh` that outlives the restart and writes progress to `update-status.json`, which the browser polls across the connection drop. `src/web/self-update.ts` splits pure helpers (unit-tested) from IO wrappers. npm installs report as non-updatable. → [architecture-invariants#self-update](docs/architecture-invariants.md#self-update)
 
 **Attachments** (live external document references; all wiring in `file-routes.ts`): a **registry** maps a stable `attachmentId` to a realpath-resolved, extension-allowlisted absolute path, so browser requests never carry arbitrary absolute paths. ⚠️ The **magic-link scanner** (`codeman://attach?...` in terminal output) is **prompt-injectable**, so its scan path is force-confined to the session workspace; a hostile prompt could otherwise exfiltrate arbitrary host files over SSE. The security gate is an extension **allowlist**, not a blocklist. `document-conversion-limiter.ts` caps converter spawns globally: without it, N large docs detected at once fork N multi-minute processes, which is a resource-exhaustion vector. → [architecture-invariants#attachments](docs/architecture-invariants.md#attachments)