rename(547): the plugin is grimoire — manifest, MCP key, hooks, env, skills

Step 3 of the Scribe -> Grimoire rename.

- Plugin `grimoire` in marketplace `grimoire-plugin`, MCP server key
  `grimoire`, so tools reach a session as mcp__plugin_grimoire_grimoire__*.
- hooks/scribe_* -> hooks/grimoire_*, their shell functions and the TMPDIR
  ledgers with them; SCRIBE_URL / SCRIBE_TOKEN / SCRIBE_HOOK_DIR /
  SCRIBE_LEDGER_DIRS -> GRIMOIRE_*; the project marker is `.grimoire`.
- skills/using-scribe -> using-grimoire, /grimoire:sync, stored processes
  arrive as grimoire-proc-<slug>; moment_actions names them the same way.
- Migration 0124 rewrites stored skill names (rule_moments,
  rule_moment_judgments, moment_mappings) from scribe:/scribe-proc- to
  grimoire:/grimoire-proc-, so a rule mounted on a skill keeps firing.
- Settings' install commands and MCP-only defaults, the docs and the
  tests follow.
- scripts/check_plugin.py drops the smoke event for a report-check hook
  that has no file in plugin/hooks.

Kept on purpose: the secret-sealing label, and the names that let backups
written as Scribe restore and be counted.

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

src/grimoire/services/retrieval_registry.py

@@ -223,7 +223,7 @@ POINTS: dict[str, Point] = dict([
 # out would not fail here. What catches that is `assert_registered`, which the
 # recorders call as the row is written.
 # Keyed by the EXACT string the extractor produces, matched by equality rather
-# than by prefix. The paths are relative to `src/` and so begin `scribe/`; a
+# than by prefix. The paths are relative to `src/` and so begin `grimoire/`; a
 # prefix spelled any other way silently matches nothing, and every site sails
 # through a check that looks like it is running.
 FAN_OUT_SITES: dict[str, tuple[str, ...]] = {