bruno: regenerate collection from canonical docs + permanent docs↔Bruno parity gate

WO4. The old collection was the drifted artifact AGENTS.md warned about:
bodies pre-truncated at their first {{var}}, routes renamed server-side
but not here (/api/notes/:media_id, /api/book-matching/search,
/api/collections/:id/rules/test), an orphan universal-progress suite for
routes that no longer exist.

scripts/gen_bruno_from_docs.py emits one OpenCollection request per
frontmatter'd endpoint doc (191 requests): gate-verified example-request
JSON as body, {{env}} params per the environment file, device-token
routes get an explicit Bearer {{device_token}} header, login/register/
refresh keep the token-capture after-response scripts that chain the
collection. Old 1:1 mirrors deleted (128); hand-authored NewDevDBSetup,
environments, and edge-case suites kept. 30 scenario files with
truncated bodies (the documented corruption) deleted — they could not
run.

internal/docs/drift_test.go gains TestBrunoMirrorsDocs: every
frontmatter'd doc must have a Bruno request with matching method+URL
shape — the collection can never silently drift from the docs again.
opencollection.yml README block replaced with the real run instructions.

make test green (9 pkgs, parity test included in internal/docs).

bruno/environments/Bookhoard.yml

@@ -1,5 +1,21 @@
 name: Bookhoard
 variables:
+  - secret: true
+    name: device_id
+  - secret: true
+    name: rule_id
+  - secret: true
+    name: annotation_id
+  - secret: true
+    name: alias_id
+  - secret: true
+    name: track_index
+  - secret: true
+    name: registration_id
+  - secret: true
+    name: unlinked_book_id
+  - secret: true
+    name: device_token
   - name: base_url
     value: http://localhost:8765
   - secret: true