fix(cli): a running server notices a CLI the installer just added

A running Codeman remembers a missing CLI for up to 5 minutes, so a status
poll never spawns a login shell, and its Run button reads that same memory.
So "Run fails, add the agent, Run again" kept saying the CLI was not
installed, right after the app had said it was ready.

install.sh now touches `cli-installed` in the data dir once a CLI has landed,
and resolve() leaves the backoff when that file's mtime changes. It is one
stat, inside the backoff branch, and buys one run of the chain, so a resolved
CLI never pays for it and a CLI that is still missing goes back to waiting.
Re-walking PATH during the backoff would have found hand installs too, but it
would put a synchronous stat of every PATH entry on the request path, where
one dead network mount freezes the server (#516), and execute candidates that
were already refused.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/architecture-invariants.md

@@ -1303,7 +1303,7 @@ On this route Node.js comes from nodejs.org (`latest-v<major>.x/SHASUMS256.txt`
 
 ⚠️ `no_admin_blocker` runs before the first download and stops for what this route cannot supply: a C/C++ toolchain on Linux (node-pty 1.1.0 compiles there; a node-pty with Linux prebuilds is what would lift this, and it is a dependency decision, not an installer one), musl, a platform nodejs.org or tmux-builds has no build for, and macOS below 15 (the tmux build's deployment target). ⚠️ Nothing between the "No-admin route" header and "End of the no-admin route" may run `sudo`, `ensure_sudo`, `run_as_root`, Homebrew or `xcode-select --install`; `run_as_root` itself refuses while `NO_ADMIN=1`, so a missed call site fails instead of prompting.
 
-**Driving the installer from a program** (`--ai-cli`, `--progress`, `install.sh preflight`, 2026-11-06). Codeman Desktop installs with no terminal: it runs `install.sh --no-admin --service --progress --ai-cli <id>|none` with `CODEMAN_NONINTERACTIVE=1` and its stdin closed, and asks the two questions in its own window (`packages/desktop/src/gui_install.rs`). `--ai-cli` answers the agent menu, so the one thing `CODEMAN_NONINTERACTIVE` used to decide by itself (the first entry of the catalogue) is the user's. ⚠️ `cli_offerable` is the ONE rule for what can be installed here: the menu, `--ai-cli` and `preflight`'s `installable` all read it, so the app's list and the menu cannot disagree. A name that is not offerable here warns and carries on, and never falls back to another CLI; a typo dies in `parse_flags` before anything runs. `install.sh agent <id>` installs one CLI and nothing else, for Codeman Desktop's *Add a coding agent*: no service, no source, no build, so it may run next to a live server, and an agent already there is a success that runs nothing. ⚠️ It calls `run_offered_cli`, checks `CLI_FOUND_PATH` of that one entry itself and only then prints `done`: `install_offered_cli`'s gate is fatal only when NO CLI is left, which is right for a first install and would report success here, where another CLI is usually present. ⚠️ The app passes `--no-admin` to both `preflight` and `agent`, because that flag decides what `cli_offerable` allows; pinned in `gui_install.rs`. ⚠️ The app runs it from a folder of its own (`Run::Agent`), so `ps` never reads an agent run as "Codeman is being installed". A running server remembers a missing CLI for up to 5 minutes (`cliResolveRetryDelayMs`), and only the CLI management routes clear that, so the app says so on its last screen and never restarts the service for it. ⚠️ `preflight` prints only JSON on stdout and changes nothing; `schema` moves only when a field changes meaning, because the app ships on its own and refuses a number it does not know. Fields may be added freely. ⚠️ `progress_phase` writes to stderr, not stdout, because a function can run inside a `$( )` that captures stdout. The phases must stay in the order of `PHASES` in `connect.html` (pinned by test), `done` must stay the last thing `main()` reports, since a run that ends without it failed, and an unknown phase is ignored by the app, so a new phase needs no new app. ⚠️ `error()` carries the text as `@@codeman error`, and the app shows the FIRST one: the ones after it are consequences (`Installation failed. Partial...`).
+**Driving the installer from a program** (`--ai-cli`, `--progress`, `install.sh preflight`, 2026-11-06). Codeman Desktop installs with no terminal: it runs `install.sh --no-admin --service --progress --ai-cli <id>|none` with `CODEMAN_NONINTERACTIVE=1` and its stdin closed, and asks the two questions in its own window (`packages/desktop/src/gui_install.rs`). `--ai-cli` answers the agent menu, so the one thing `CODEMAN_NONINTERACTIVE` used to decide by itself (the first entry of the catalogue) is the user's. ⚠️ `cli_offerable` is the ONE rule for what can be installed here: the menu, `--ai-cli` and `preflight`'s `installable` all read it, so the app's list and the menu cannot disagree. A name that is not offerable here warns and carries on, and never falls back to another CLI; a typo dies in `parse_flags` before anything runs. `install.sh agent <id>` installs one CLI and nothing else, for Codeman Desktop's *Add a coding agent*: no service, no source, no build, so it may run next to a live server, and an agent already there is a success that runs nothing. ⚠️ It calls `run_offered_cli`, checks `CLI_FOUND_PATH` of that one entry itself and only then prints `done`: `install_offered_cli`'s gate is fatal only when NO CLI is left, which is right for a first install and would report success here, where another CLI is usually present. ⚠️ The app passes `--no-admin` to both `preflight` and `agent`, because that flag decides what `cli_offerable` allows; pinned in `gui_install.rs`. ⚠️ The app runs it from a folder of its own (`Run::Agent`), so `ps` never reads an agent run as "Codeman is being installed". A running server remembers a missing CLI for up to 5 minutes (`cliResolveRetryDelayMs`), and Run reads that memory, so `mark_cli_installed` touches `cli-installed` in the data dir and `resolve()` leaves the backoff when that file's mtime changes. ⚠️ That check is one `stat` inside the backoff branch and buys one run of the chain. Never replace it with a re-walk of PATH during the backoff: that puts a synchronous stat of every PATH entry on the request path (#516) and executes candidates already refused. The app never restarts the service for this. Only `install.sh` writes the marker, always under `~/.codeman`, so a CLI installed by hand, or another `CODEMAN_INSTANCE`, waits out the backoff as before, and so does a server older than this. ⚠️ `preflight` prints only JSON on stdout and changes nothing; `schema` moves only when a field changes meaning, because the app ships on its own and refuses a number it does not know. Fields may be added freely. ⚠️ `progress_phase` writes to stderr, not stdout, because a function can run inside a `$( )` that captures stdout. The phases must stay in the order of `PHASES` in `connect.html` (pinned by test), `done` must stay the last thing `main()` reports, since a run that ends without it failed, and an unknown phase is ignored by the app, so a new phase needs no new app. ⚠️ `error()` carries the text as `@@codeman error`, and the app shows the FIRST one: the ones after it are consequences (`Installation failed. Partial...`).
 
 ⚠️ **git is judged by whether it works, never by `command -v`.** On a Mac without the Xcode Command Line Tools `/usr/bin/git` is a stub that opens Apple's install dialog, so `check_git` judges that path by `xcode-select -p` and never executes it; any other git is asked for `--version`. `scripts/git-hooks.mjs` has the matching guard (no `.git`, no `git` call), because postinstall runs it on every `npm install`. Without a working git the source is an archive (`fetch_source_archive`, GitHub's `archive/<ref>.tar.gz` or `CODEMAN_TARBALL_URL`) and the install directory carries the marker `.install-source`, which `detectInstallKind` reads as `archive` (the name is pinned across both files by `test/install-sh-invariants.test.ts`). ⚠️ An archive install is replaced as a WHOLE, never patched in place: nothing says which files a newer version dropped, and a stale `src/*.ts` would be compiled. The new tree is fetched and built in `<install dir>.new` and `finish_source_swap` moves it into place only after `npm run build` succeeded, so a failed update leaves the running install untouched; a re-run on a machine that has gained a working git stages a clone instead, which turns the install back into a git one. ⚠️ `download`/`download_to_stdout` resolve `DOWNLOADER` themselves (`require_downloader`): only `main()` used to set it, so a subcommand that downloads died on `set -u` with the message swallowed by the step log.
 

docs/wiki/Installation.md

@@ -100,8 +100,8 @@ and a re-run with `--lan` or `--tailscale` keeps the password the service alread
 terminal needed (`--ai-cli claude`, `--ai-cli codex`, ...), and `--ai-cli none` skips it.
 To add an agent later, `install.sh agent codex` installs that one and changes nothing else:
 it does not touch Codeman or its service, and an agent that is already there is left alone.
-Codeman Desktop does the same from *Add a coding agent*. A running Codeman can take a few
-minutes to notice the new agent; reload the page if it does not show up.
+Codeman Desktop does the same from *Add a coding agent*. A running Codeman notices the new
+agent at once; reload an open page to see it.
 
 **Automation and CI**: with no terminal attached, any step that would change the system
 aborts with instructions instead of running silently. Set `CODEMAN_NONINTERACTIVE=1` to