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>

docs/api-keys-and-mcp.md

@@ -35,7 +35,7 @@ Click **Revoke** next to the key in the keys table and confirm. Revoked keys are
 Grimoire exposes itself as a set of MCP tools that Claude (and other MCP clients)
 can use to read and write your notes, tasks, projects, rulebooks, and more. The
 server is **built into the app** — it is mounted as a streamable-HTTP endpoint
-at **`/mcp`** on the running Grimoire instance (`src/scribe/mcp/server.py`). There
+at **`/mcp`** on the running Grimoire instance (`src/grimoire/mcp/server.py`). There
 is nothing to install: no wheel, no separate package, no CLI. You connect a
 client straight to the URL with a Bearer token.
 
@@ -90,7 +90,7 @@ specific project at a dev instance or an admin key.
 ### Available Tools
 
 There are well over a hundred tools and they change with the app, so the
-registration in **`src/scribe/mcp/tools/`** is the reference. By family:
+registration in **`src/grimoire/mcp/tools/`** is the reference. By family:
 
 | Family | Examples | Purpose |
 |--------|----------|---------|
@@ -111,4 +111,4 @@ registration in **`src/scribe/mcp/tools/`** is the reference. By family:
 Server-level usage guidance — when to reach for each entity, the
 recall-before-acting reflex, and the rulebook conventions — is delivered to the
 client automatically via the MCP server's `instructions` block (defined in
-`src/scribe/mcp/server.py`).
+`src/grimoire/mcp/server.py`).