rename(547): the repo is FabledGrimoire, and no stray "scribe" is left

The forge repo is now bvandeusen/FabledGrimoire. The plugin marketplace default,
the install commands in the docs and plugin README, the CI requirements title and
the example repo URLs in comments and tests follow it. docs/development.md now
names the image the build actually publishes, fabledgrimoire.

Two test names still said "scribes_own"; they now say "grimoires_own".

What still says scribe does so on purpose:
- the backup reader's accepted archive names and prefix;
- the label every stored secret is sealed under;
- the notes on keeping an old install's database names;
- the old migrations.

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

scripts/bench_ollama.py

@@ -3,7 +3,7 @@
 # requires-python = ">=3.10"
 # dependencies = ["httpx>=0.27"]
 # ///
-"""Benchmark Ollama models for FabledScribe chat / curator workloads.
+"""Benchmark Ollama models for FabledGrimoire chat / curator workloads.
 
 Measures time-to-first-token, total wall time, and tokens/sec for each
 (model, scenario) pair. Designed to be runnable against both local and