rename(547): the server is grimoire — package, image, DB defaults, backups

Step 2 of the Scribe -> Grimoire rename.

- src/scribe -> src/grimoire, and every import, patch target, module path,
  hypercorn entry point and `python -m grimoire.restore` with it; pyproject,
  uv.lock and the frontend package are named grimoire.
- Image git.fabledsword.com/bvandeusen/fabledgrimoire; CI's Postgres service
  runs as grimoire / grimoire_test.
- Compose files default the DB user, database and (prod) volume to grimoire,
  each overridable from .env, so an install created as Scribe keeps its data
  by setting POSTGRES_USER, POSTGRES_DB and PGDATA_VOLUME.
- Backups are written as grimoire-<ts>.tar with format grimoire-backup-tar.
  Archives named scribe-* with the scribe-backup-tar manifest still restore
  and are still counted at the destination (folder and S3), with tests.
- Exports, the MCP auth realm, the ASGI scope key and the persistent logger
  carry the new name.

Kept on purpose: the secret-sealing key label stays "scribe.secrets.v1",
because every stored secret was derived under it.

Plugin identity (plugin name, hooks, env vars, .scribe marker, skills) is
step 3.

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

tests/test_routes_platforms.py

@@ -5,7 +5,7 @@ import inspect
 
 
 def test_platforms_blueprint_registered_in_app():
-    from scribe.app import create_app
+    from grimoire.app import create_app
     app = create_app()
     assert "platforms" in app.blueprints
     rules = {(r.rule, m) for r in app.url_map.iter_rules() for m in r.methods}
@@ -22,7 +22,7 @@ def test_platforms_blueprint_registered_in_app():
 def test_writes_to_the_catalog_and_to_a_project_take_the_caller():
     """The catalog's admin gate and the project's write gate both live in the
     service, so every write must be handed the caller to check."""
-    from scribe.services import platforms as svc
+    from grimoire.services import platforms as svc
     for name in ("create_platform", "update_platform", "set_project_platforms",
                  "project_platforms"):
         assert "user_id" in inspect.signature(getattr(svc, name)).parameters