docs(skill): hooks are a setting now, not who created the directory

The workspace-hooks install makes the skill's central hooks rule wrong in the
cautious direction. Six places told a worker that a linked case or a raw
workingDir has no `stop`/`blocked` and that send-and-wait cannot be trusted
there, so an agent would hand-roll output-marker synchronization in exactly the
workspaces where `wait:true` now works.

Rewritten against the setting rather than directory provenance:

- verbs.md §5.1: the where-to-spawn table, the rule paragraph (now naming
  `workspaceHooksEnabled`, default ON, the add-only merge, and the boot sweep of
  recovered sessions), and the silent-failure warning. The three cases that stay
  hook-less regardless are called out: remote SSH sessions, docker cases that
  opted out, and a workspace Codeman cannot write to.
- verbs.md §5.3: the send-and-wait precondition is "the workspace has the hooks
  block", not "a case Codeman created".
- endpoints.md: the Signals-by-mode table is now keyed on the setting, with rows
  for OFF, for remote/docker-opt-out, and for a session from an older server.
  The old create-path grep list becomes a "before 1.18.x" note.
- SKILL.md §2 + the cost list, recipes.md Flow-1 contrast, messaging.md step 1.

"Check, do not assume" is kept and promoted to the load-bearing habit, because
the setting is not visible from the call and a session created by an older server
that has not restarted still has nothing.

The `spawn_worker` hooks grep STAYS: it guards the setting being off, remote
sessions, and older servers. Only its diagnostic changes, since "pick an unused
name" is no longer the fix. That text lives in both the §0 heredoc and
`preamble.sh`, which `test/agent-skill.test.ts` pins byte-identical, so both are
patched with the same bytes.

Docs only, no behavior change. 23 skill tests green, full test:ci 5109 passed.

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

skills/codeman/reference/verbs.md

@@ -30,28 +30,40 @@ wrong directory.** `quick-start` with a new `caseName` does not find your repo:
 | Where the work is | Call | Hooks, and therefore signals |
 |-------------------|------|------------------------------|
 | a fresh scratch dir (throwaway experiments) | `POST /api/v1/quick-start {"caseName":"scratch-1","mode":"claude"}` with a **new** case name | Codeman creates the directory and **writes hooks**: `stop` and `blocked` fire, send-and-wait is trustworthy |
-| a linked case (a real repo in the linked-cases registry) | same call with the linked name | **no hooks**, unless that repo already carries a Codeman hooks block from some earlier path. Check before relying on `stop` |
-| any other absolute path, e.g. a git worktree you made | `POST /api/v1/sessions {"workingDir":"/abs/path","mode":"claude"}` then `POST /api/v1/sessions/:id/interactive` | **no hooks**: no `stop`, no `blocked`, synchronize with markers ([§5.5](#55-markers-for-hook-less-workers)) |
+| a linked case (a real repo in the linked-cases registry) | same call with the linked name | **hooks installed at session create**, so `stop` fires here too. Not guaranteed: the operator can turn it off. Check |
+| any other absolute path, e.g. a git worktree you made | `POST /api/v1/sessions {"workingDir":"/abs/path","mode":"claude"}` then `POST /api/v1/sessions/:id/interactive` | same: **hooks installed at session create**, subject to the same setting. Check |
 
 Read `.data.casePath` back from the `quick-start` response and check it is where you
 meant. `caseName` accepts letters, digits, `-` and `_` only, and it resolves through
 the linked-cases registry **first**, so a name that collides with something the user
 linked in lands in that real repo rather than a scratch dir.
 
-**The rule is who created the directory.** Codeman writes hooks only where it created
-the workspace itself: `quick-start` on a NEW case name, `POST /api/cases`, the repo
-clone, the docker quick-create. Those hooks persist, so a scratch case created last
-week still has them today. A directory that already existed when Codeman first pointed
-at it never gets them: `POST /api/cases/link` writes only the name-to-path entry in
-`linked-cases.json`, and quick-start into an existing path runs
-`refreshStaleCodemanHooks()`, which by design returns immediately when there is no
-Codeman hooks block to refresh. Source-verified by exhaustive call-site grep, and
-measured: a worker in a linked case never resolved a parked `wait?until=stop,exit`
-across twelve consecutive 60 s rounds, although it had finished its turn.
+**The rule is a setting, not who created the directory.** Every claude create path
+(`POST /api/sessions`, `POST /api/quick-start`, and quick-start's docker branch) now
+installs the hooks block into the workspace, and the server sweeps the workspaces of
+sessions it recovers at boot. So a linked case, a cloned repo and a hand-made git
+worktree all get `stop`/`blocked`, not just a scratch case Codeman scaffolded. The
+install is an **add-only merge**: a user's own hook entries and every other settings
+key survive, and a malformed settings file is left alone.
 
-**Check, do not assume.** Read `<casePath>/.claude/settings.local.json` with your own
-file tools and look for `/api/hook-event`. Present means `stop`/`blocked` will fire;
-absent means they never will.
+The gate is the synced **`workspaceHooksEnabled`** setting, **default ON** (an absent
+key counts as ON). Turned OFF, the old behavior returns exactly: an existing Codeman
+block is still refreshed when stale, but one is never added, and the boot sweep is
+skipped. Three cases stay hook-less regardless: **remote SSH sessions** (their
+`workingDir` is a path on another host), **docker cases that opted out**, and any
+workspace Codeman cannot write to.
+
+Until this landed, hooks existed only where Codeman created the directory, and the
+gap was invisible: a worker in a linked case never resolved a parked
+`wait?until=stop,exit` across twelve consecutive 60 s rounds, although it had finished
+its turn. If you are driving an older server, assume that older rule.
+
+**Check, do not assume.** This is now the load-bearing habit, because you cannot tell
+from the call which way the setting is set, and an old session created before the fix
+on a server that has not restarted still has nothing. Read
+`<casePath>/.claude/settings.local.json` with your own file tools and look for
+`/api/hook-event`. Present means `stop`/`blocked` will fire; absent means they never
+will, whatever kind of workspace it is.
 
 ⚠️ **The hook-less failure is silent, and it is the worst one in this skill.**
 `"wait":true` is still **accepted** on a hook-less claude session: the 400 you may be
@@ -59,9 +71,10 @@ expecting is about session *mode*, not about hooks. With no `stop` to resolve on
 default signal set falls back to the heuristic `idle`, which flaps mid-turn, so
 send-and-wait returns "finished" while the worker is still working, and the
 `last-response` you read next hands you the **previous** turn's text. No error is
-raised anywhere. In any workspace Codeman did not create, use markers
-([§5.5](#55-markers-for-hook-less-workers)) and treat send-and-wait's answer as
-unreliable.
+raised anywhere. Hooks are installed by default now, so this is rarer than it was, but
+the failure is unchanged when it happens: in any workspace whose settings file has no
+`/api/hook-event`, use markers ([§5.5](#55-markers-for-hook-less-workers)) and treat
+send-and-wait's answer as unreliable.
 
 Spawning at a raw path:
 
@@ -238,11 +251,13 @@ fi
 
 ### 5.3 Send a task and wait
 
-⚠️ **Precondition: this is the call to prefer only for a claude worker in a workspace
-Codeman created**, because it is trustworthy only when the `stop` hook exists. On a
-linked case or a raw path it is accepted, resolves on flapping `idle`, and reports a
-turn as finished while it is still running, with no error anywhere. Check hooks first
-([§5.1](#51-where-to-spawn)); where they are absent, use markers
+⚠️ **Precondition: a claude worker whose workspace has the hooks block**, because
+this is trustworthy only when the `stop` hook exists. Every claude create path installs
+it by default now, so that is the normal case, but where it is absent (the setting off,
+a remote session, an older server) the call is still accepted, resolves on flapping
+`idle`, and reports a turn as finished while it is still running, with no error
+anywhere. Check hooks first ([§5.1](#51-where-to-spawn)); where they are absent, use
+markers
 ([§5.5](#55-markers-for-hook-less-workers)).
 
 It registers the waiter *before* typing,