feat(skill): ship the codeman agent skill as a Claude Code plugin from the repo's own marketplace

`.claude-plugin/marketplace.json` at the repo root makes
`/plugin marketplace add Ark0N/Codeman` work, and the one plugin it lists is
the repo itself (`source: "./"`), whose one component is `skills/codeman/`.
So `/plugin install codeman@codeman` is a third install route next to
`npx skills add` and `codeman skill install`, and the skill shows up in the
plugin directories that index Claude Code marketplaces.

Both manifests carry package.json's version: `scripts/sync-plugin-version.mjs`
rewrites them inside `version-packages`, right after `changeset version`, and
`test/plugin-manifest.test.ts` pins the equality, the skill's frontmatter name
(without it the installed skill would be named after a versioned cache dir),
and that no other plugin component (`commands/`, `agents/`, `hooks/`,
`.mcp.json`, `settings.json`) appears at the repo root, since an install would
silently ship it.

Verified with `claude plugin validate` (one expected warning: CLAUDE.md at a
plugin root is not plugin context) and a local marketplace add, install,
details, uninstall cycle against a clean checkout of this commit.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

CLAUDE.md

@@ -6,7 +6,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 >
 > **This file is in `.prettierignore` on purpose.** Prettier's markdown printer escapes underscores inside the glob-heavy paths used throughout (`agent-*.jsonl` became `agent-\_.jsonl`, collapsing backtick spans and corrupting a whole paragraph). Do not remove the ignore entry, and do not run `prettier --write` on it.
 >
-> **Repo root is kept short on purpose** (the README sits below the file listing on GitHub). Config lives in `config/` (`eslint.config.js`, `knip.json`, the vitest configs), Prettier's config is the `"prettier"` key in `package.json`, and `SECURITY.md` is under `.github/`. Root-only files are the ones tools genuinely require there: `CLAUDE.md` + `AGENTS.md` (loaded from the root by Claude Code / Codex), `CHANGELOG.md` (changesets writes it next to `package.json`), `tsconfig.json`, `.editorconfig`, `.nvmrc`/`.npmrc`, `.prettierignore` (resolved relative to cwd), `LICENSE` (GitHub detection), `.dockerignore` (the build context is the repo root, so Docker resolves it there and nowhere else) and `install.sh` (its raw URL is the published install one-liner). Don't relocate those.
+> **Repo root is kept short on purpose** (the README sits below the file listing on GitHub). Config lives in `config/` (`eslint.config.js`, `knip.json`, the vitest configs), Prettier's config is the `"prettier"` key in `package.json`, and `SECURITY.md` is under `.github/`. Root-only files are the ones tools genuinely require there: `CLAUDE.md` + `AGENTS.md` (loaded from the root by Claude Code / Codex), `CHANGELOG.md` (changesets writes it next to `package.json`), `tsconfig.json`, `.editorconfig`, `.nvmrc`/`.npmrc`, `.prettierignore` (resolved relative to cwd), `LICENSE` (GitHub detection), `.dockerignore` (the build context is the repo root, so Docker resolves it there and nowhere else) and `install.sh` (its raw URL is the published install one-liner). `.claude-plugin/` (`plugin.json` + `marketplace.json`) is root-only for the same reason: `/plugin marketplace add Ark0N/Codeman` reads it from the repo root and nowhere else, which makes the repo its own plugin marketplace with the repo itself (`source: "./"`) as the one plugin, whose one component is `skills/codeman/`. Both manifests carry `package.json`'s version, synced by `scripts/sync-plugin-version.mjs` inside `version-packages` and pinned by `test/plugin-manifest.test.ts`, which also refuses any other plugin component (`commands/`, `agents/`, `hooks/`, `.mcp.json`, `settings.json`) appearing at the root, since an install would silently ship it. Don't relocate those.
 
 ## Quick Reference
 
@@ -193,7 +193,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 
 **Input**: `session.writeViaMux()` for programmatic/curl input via tmux `send-keys -l` + `send-keys Enter`, single-line only. Interactive **browser** input goes through a durable **exactly-once** layer: a stable `clientId` + monotonic per-session `seq` persisted to localStorage until the server ACKs, so a dropped link cannot lose or double-deliver a prompt. `ws-connection-registry.ts` supersedes only same-TAB reconnects, so two tabs on one session coexist. → [architecture-invariants#input-delivery-and-ws-resilience](docs/architecture-invariants.md#input-delivery-and-ws-resilience)
 
-**Agent wait primitives**: bounded long-polls so an agent driving Codeman from a shell can block instead of poll: `GET /api/sessions/:id/wait` (lifecycle signal), `GET /api/sessions/:id/wait-output` (literal substring, **never** regex) and `wait`/`waitTimeout` on `POST /api/sessions/:id/input`. Registry in `session-wait-registry.ts` (pure, no `Session` reference), bounds in `config/agent-wait.ts`. ⚠️ **A timeout is a 200** (`wait.timedOut`), never an error, so callers loop over short waits. ⚠️ `stop`/`blocked` are hook-driven and fire for **`claude` and `deepseek` ONLY** (`shell` installs none either); asking for one explicitly on any other mode is a 400, the default set silently drops them. `deepseek` qualifies because the DeepSeek Harness TUI REPORTS idle/working/blocked to its supervisor and Codeman is that supervisor (`deepseek-status-shim.ts`), so its signals are definitive rather than inferred — `hooksAvailableForMode()` in `session-wait-registry.ts` is the one place that rule lives. ⚠️ Send-and-wait registers the waiter BEFORE the write (a separate POST-then-wait races and reports the PREVIOUS turn), and both teardown paths must `notifySignal('exit')` BEFORE `cancelAll()`. ⚠️ Client-hangup abort listens on **`reply.raw`** guarded by `writableFinished`: on `req.raw`, `close` fires when the request BODY ends, which on a POST killed every send-and-wait instantly and no `app.inject()` test could see it. ⚠️ Worker liveness cannot come from `session.pid` — for a tmux session that is the local attach client, which outlives a worker dying inside its pane — so it is probed at the mux layer (`isPaneDead`, ~750 ms cache) on blocking waits only, never on the input hot path. ⚠️ Signals are edge-triggered with no history: one that fires with no waiter registered is unobservable afterwards, so gather fan-outs with send-and-wait or latched `wait-output` markers, never fire-and-forget-then-sequential-signal-waits. ⚠️ **`deepseek` is therefore the one non-claude mode the skill drives like claude** — `spawn_workers alpha beta:deepseek` is a mixed fleet in one call, and `sendwait`/`last_text` need no variant. Two traps are baked into the preamble rather than left to the agent: the harness's boot `idle` report lands ~300 ms BEFORE its composer paints (2.26 s vs 2.56 s, measured), so readiness must come from the composer and never from the signal, or a send-and-wait resolves on the boot edge and reports a turn that never ran; and `sendwait` asks for `wait:"stop,exit"` rather than the default set, because that set also carries `idle`, which for an external CLI is inferred from output stabilization — on a dsh worker whose TUI repaints rarely, a re-wait resolved in 0 ms with `signal:"idle"` on a turn with minutes left to run. The primitives are packaged as the **`skills/codeman` agent skill**: installable via `codeman skill install [--case <name>]` / `skill uninstall`, or auto-injected into a case's `.claude/skills/` on Claude session create behind `agentSkillEnabled` (SYNCED, default OFF). Injection is ADD-ONLY at create, marker-owned (`applyAgentSkill` in `hooks-config.ts` never touches an unmarked user copy) and refuses symlinks (this repo's own `.claude/skills/codeman` is a symlink to the source, which the injector must never write through). ⚠️ Claude Code loads a same-named USER-LEVEL skill (`~/.claude/skills/codeman`, written once by `codeman skill install` with no `--case`) over the per-case copy, and nothing used to refresh it: a stale Aug-9 user copy shadowed every fresh injection (2026-08-14: agents ran the old recipes, spawned workers serially and lost their lineage arcs), so session create now also refreshes a marker-owned user copy (`refreshUserAgentSkill`; refresh-only, never installs, foreign/symlink refused). Session create additionally pre-seeds the skill's §0 preamble cache (`seedAgentSessionPreamble` → `${XDG_CACHE_HOME:-~/.cache}/codeman-agent-<id>.sh`, local claude sessions only), single-sourced from `skills/codeman/preamble.sh` and pinned byte-identical to SKILL.md's §0 heredoc by `test/agent-skill.test.ts`, so the skill's bootstrap is a two-line loader instead of a ~150-line paste the model types out (~47 s of generation, measured live). → [architecture-invariants#agent-wait-primitives](docs/architecture-invariants.md#agent-wait-primitives), `docs/api-reference.md`
+**Agent wait primitives**: bounded long-polls so an agent driving Codeman from a shell can block instead of poll: `GET /api/sessions/:id/wait` (lifecycle signal), `GET /api/sessions/:id/wait-output` (literal substring, **never** regex) and `wait`/`waitTimeout` on `POST /api/sessions/:id/input`. Registry in `session-wait-registry.ts` (pure, no `Session` reference), bounds in `config/agent-wait.ts`. ⚠️ **A timeout is a 200** (`wait.timedOut`), never an error, so callers loop over short waits. ⚠️ `stop`/`blocked` are hook-driven and fire for **`claude` and `deepseek` ONLY** (`shell` installs none either); asking for one explicitly on any other mode is a 400, the default set silently drops them. `deepseek` qualifies because the DeepSeek Harness TUI REPORTS idle/working/blocked to its supervisor and Codeman is that supervisor (`deepseek-status-shim.ts`), so its signals are definitive rather than inferred — `hooksAvailableForMode()` in `session-wait-registry.ts` is the one place that rule lives. ⚠️ Send-and-wait registers the waiter BEFORE the write (a separate POST-then-wait races and reports the PREVIOUS turn), and both teardown paths must `notifySignal('exit')` BEFORE `cancelAll()`. ⚠️ Client-hangup abort listens on **`reply.raw`** guarded by `writableFinished`: on `req.raw`, `close` fires when the request BODY ends, which on a POST killed every send-and-wait instantly and no `app.inject()` test could see it. ⚠️ Worker liveness cannot come from `session.pid` — for a tmux session that is the local attach client, which outlives a worker dying inside its pane — so it is probed at the mux layer (`isPaneDead`, ~750 ms cache) on blocking waits only, never on the input hot path. ⚠️ Signals are edge-triggered with no history: one that fires with no waiter registered is unobservable afterwards, so gather fan-outs with send-and-wait or latched `wait-output` markers, never fire-and-forget-then-sequential-signal-waits. ⚠️ **`deepseek` is therefore the one non-claude mode the skill drives like claude** — `spawn_workers alpha beta:deepseek` is a mixed fleet in one call, and `sendwait`/`last_text` need no variant. Two traps are baked into the preamble rather than left to the agent: the harness's boot `idle` report lands ~300 ms BEFORE its composer paints (2.26 s vs 2.56 s, measured), so readiness must come from the composer and never from the signal, or a send-and-wait resolves on the boot edge and reports a turn that never ran; and `sendwait` asks for `wait:"stop,exit"` rather than the default set, because that set also carries `idle`, which for an external CLI is inferred from output stabilization — on a dsh worker whose TUI repaints rarely, a re-wait resolved in 0 ms with `signal:"idle"` on a turn with minutes left to run. The primitives are packaged as the **`skills/codeman` agent skill**: installable via `codeman skill install [--case <name>]` / `skill uninstall`, as a Claude Code plugin from the repo's own marketplace (`/plugin marketplace add Ark0N/Codeman` + `/plugin install codeman@codeman`, see the root-files note above), or auto-injected into a case's `.claude/skills/` on Claude session create behind `agentSkillEnabled` (SYNCED, default OFF). Injection is ADD-ONLY at create, marker-owned (`applyAgentSkill` in `hooks-config.ts` never touches an unmarked user copy) and refuses symlinks (this repo's own `.claude/skills/codeman` is a symlink to the source, which the injector must never write through). ⚠️ Claude Code loads a same-named USER-LEVEL skill (`~/.claude/skills/codeman`, written once by `codeman skill install` with no `--case`) over the per-case copy, and nothing used to refresh it: a stale Aug-9 user copy shadowed every fresh injection (2026-08-14: agents ran the old recipes, spawned workers serially and lost their lineage arcs), so session create now also refreshes a marker-owned user copy (`refreshUserAgentSkill`; refresh-only, never installs, foreign/symlink refused). Session create additionally pre-seeds the skill's §0 preamble cache (`seedAgentSessionPreamble` → `${XDG_CACHE_HOME:-~/.cache}/codeman-agent-<id>.sh`, local claude sessions only), single-sourced from `skills/codeman/preamble.sh` and pinned byte-identical to SKILL.md's §0 heredoc by `test/agent-skill.test.ts`, so the skill's bootstrap is a two-line loader instead of a ~150-line paste the model types out (~47 s of generation, measured live). → [architecture-invariants#agent-wait-primitives](docs/architecture-invariants.md#agent-wait-primitives), `docs/api-reference.md`
 
 **Agent-created case marker** (`src/agent-case-marker.ts`): a case directory `POST /api/quick-start` **creates** for an agent-driven spawn gets a `.codeman-agent-case.json` marker, so the scratch workspaces a long orchestration leaves behind (one per worker, and deleting the session does not remove them) can still be told apart from the user's real projects months later. `GET /api/cases` publishes it as `agentCreated`; `GET /api/cases/agent-created` is the read-only cleanup listing, adding `inUse` (a live session's `workingDir` is that case) and `modifiedAt`; Add Case → Manage badges each one and offers a review-then-delete sweep. The signal is the skill preamble's `X-Codeman-Agent-Origin` header (or an `agentOrigin` body field), falling back to a RESOLVED `parentSessionId` — nothing in the browser UI sets lineage, so a create request naming its spawning session came from an agent by construction, and that fallback is what still labels workers spawned by a stale skill copy. ⚠️ **Only the branch that CREATES the directory may write it.** A linked case, a cloned repo or any pre-existing path must never be labelled: the label drives a recursive-delete affordance, and mislabelling someone's repo there is the one failure mode that costs real work. `POST /api/sessions` takes an existing `workingDir`, so it writes no marker at all, by construction. ⚠️ Reading is TOTAL: anything that is not a well-formed version-1 marker (truncated write, hand-edited junk) reads as *not* agent-created rather than as a half-trusted entry, and deleting the file is the supported way to adopt a scratch case as a real one — which is what the `note` written into it tells whoever finds it. ⚠️ Removal stays on the existing `DELETE /api/cases/:name`, one name at a time, so there is exactly ONE recursive-delete path; the UI's sweep names every directory in its confirm and EXCLUDES an `inUse` case outright rather than confirming it away. ⚠️ Marker in the case dir rather than a registry under `~/.codeman`: it survives a wiped data dir or a different instance, is removed by the same `rm -rf` that removes the case (so no stale-entry pruning), and a user who runs `ls -a` can see what labelled their directory. Adding the header changed the preamble, so `CODEMAN_PREAMBLE` was bumped (1.22.0) — a cached copy is version-checked, and forgetting the bump leaves every already-seeded agent sending the old headers. Tests: `test/agent-case-marker.test.ts`, `test/routes/agent-case-marker-routes.test.ts`.