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_retrieval_warnings.py

@@ -25,7 +25,7 @@ from __future__ import annotations
 
 import pytest
 
-from scribe.services.retrieval_telemetry import (
+from grimoire.services.retrieval_telemetry import (
     WARN_FLOOR_EPSILON_DEFAULT, WARN_MIN_CALLS_DEFAULT,
     _compute_warnings, _num, _silent_surfaces,
 )
@@ -105,7 +105,7 @@ def test_an_arm_not_known_to_log_unconditionally_is_exempt(monkeypatch) -> None:
     """
     from dataclasses import replace
 
-    from scribe.services import retrieval_registry as reg
+    from grimoire.services import retrieval_registry as reg
 
     patched = dict(reg.POINTS)
     patched["auto_inject"] = replace(patched["auto_inject"],
@@ -188,7 +188,7 @@ def test_each_corpus_is_sent_only_to_a_tool_that_takes_it() -> None:
     `REVIEWABLE` itself, so it goes red in either direction: the rules text
     naming the tool while no rule arm is reviewable, or a rule arm becoming
     reviewable while the text still says there is no sample."""
-    from scribe.services.retrieval_review import REVIEWABLE
+    from grimoire.services.retrieval_review import REVIEWABLE
 
     ws = warn(
         {},
@@ -236,7 +236,7 @@ def test_every_registered_source_stays_quiet_when_healthy() -> None:
     A guard that cannot pass cleanly is not a guard — if a healthy window
     produced warnings, every assertion above would be meaningless.
     """
-    from scribe.services.retrieval_registry import POINTS
+    from grimoire.services.retrieval_registry import POINTS
 
     healthy = {s: src(calls=100, zero_result_calls=40, p10=0.90)
                for s in POINTS}