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>

.forgejo/workflows/ci.yml

@@ -55,7 +55,7 @@ permissions:
 
 env:
   REGISTRY: git.fabledsword.com
-  IMAGE: git.fabledsword.com/bvandeusen/fabledscribe
+  IMAGE: git.fabledsword.com/bvandeusen/fabledgrimoire
 
 jobs:
   typecheck:
@@ -193,11 +193,11 @@ jobs:
         # Same image as the shipped compose files: Postgres 17 with pgvector.
         image: pgvector/pgvector:pg17
         env:
-          POSTGRES_USER: scribe
+          POSTGRES_USER: grimoire
           POSTGRES_PASSWORD: ci_integration
-          POSTGRES_DB: scribe_test
+          POSTGRES_DB: grimoire_test
         options: >-
-          --health-cmd "pg_isready -U scribe"
+          --health-cmd "pg_isready -U grimoire"
           --health-interval 10s
           --health-timeout 5s
           --health-retries 10
@@ -235,7 +235,7 @@ jobs:
           test "$(printf '%s\n' "$PG" | grep -c .)" -eq 1
           PG_IP=$(docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' "$PG")
           test -n "$PG_IP"
-          export DATABASE_URL="postgresql+asyncpg://scribe:ci_integration@${PG_IP}:5432/scribe_test"
+          export DATABASE_URL="postgresql+asyncpg://grimoire:ci_integration@${PG_IP}:5432/grimoire_test"
           # Wait for Postgres. The run: shell is dash (no bash /dev/tcp), so use Python.
           /opt/venv/bin/python - "$PG_IP" <<'PY'
           import socket, sys, time