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/messaging.md

@@ -196,12 +196,14 @@ idle:
 The contract an orchestrator follows for any fleet of two or more messaging workers.
 Every topology in the next section is this protocol plus a wiring diagram.
 
-1. **Spawn with a name, and with hooks.** Use `quick-start` with `sessionName` (the
-   `--name` gate above), and let it **CREATE** the case. ⚠️ Linking does NOT install
-   hooks (`POST /api/cases/link` writes only the name-to-path entry), and neither does a
-   bare `POST /api/sessions`; a worker in a directory Codeman did not create has no
-   `stop`/`blocked` signals at all and every synchronization below degrades to output
-   markers. The discriminator is who created the directory, not whether it exists now.
+1. **Spawn with a name, and confirm hooks.** Use `quick-start` with `sessionName` (the
+   `--name` gate above). Session create installs the hooks block into the workspace
+   whatever kind it is, so a linked case and a raw `POST /api/sessions` path both get
+   `stop`/`blocked` by default. ⚠️ Not unconditionally: the operator can turn
+   `workspaceHooksEnabled` off, remote SSH sessions never get hooks, and a session from
+   an older server may have none, and without them every synchronization below degrades
+   to output markers. Grep `<casePath>/.claude/settings.local.json` for
+   `/api/hook-event` at spawn rather than inferring it from how the directory got there.
 2. **Readiness before addressing.** Flow 1's ladder per worker, then the availability
    probe. A worker that fails the probe is an HTTP worker for the rest of the run; that
    is a routing decision, not an error.