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>

tests/test_retrieval_miss_route.py

@@ -44,10 +44,10 @@ TUNING_TOOLS = ("retrieval_telemetry", "update_rule", "retrieval_surfaces",
 
 
 def _skill() -> str:
-    # The route lives in missed-retrieval.md, a reference file of using-scribe;
+    # The route lives in missed-retrieval.md, a reference file of using-grimoire;
     # the skill is SKILL.md and its references read together.
     from tests.helpers import skill_text
-    return skill_text("using-scribe")
+    return skill_text("using-grimoire")
 
 
 def _instructions() -> str:
@@ -62,7 +62,7 @@ def test_the_route_names_every_tool_it_depends_on():
     text = _skill()
     missing = [t for t in TUNING_TOOLS if t not in text]
     assert not missing, (
-        f"using-scribe no longer names {missing}. These tools reach a session "
+        f"using-grimoire no longer names {missing}. These tools reach a session "
         f"through this skill and nowhere else — when they were named on no "
         f"surface at all, the tuning loop logged zero events in its lifetime."
     )
@@ -140,7 +140,7 @@ def test_the_route_stays_off_the_index():
 
     It carries no pointer to this route, because the index is not a rulebook:
     a missed rule is noticed mid-work, not at session start, and the spec asks server instructions for the
-    workflow across tools, not stance. using-scribe states the route (the tests
+    workflow across tools, not stance. using-grimoire states the route (the tests
     above pin it); the index keeps what_might_apply, the tool that opens it.
 
     Whitespace-flattened before matching: the block is hard-wrapped, so a