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/media-items/create_media_item.yml

@@ -0,0 +1,39 @@
+info:
+  name: Create Media Item
+  type: http
+  seq: 4
+
+http:
+  method: POST
+  url: '{{base_url}}/api/media-items'
+  auth: inherit
+  body:
+    type: json
+    data: |-
+      {
+        "library_id": "550e8400-e29b-41d4-a716-446655440000",
+        "title": "Example Book Title",
+        "author": "Jane Doe",
+        "isbn": "978-0-123456-78-9",
+        "description": "A great book about technology",
+        "file_path": "/library/books/example.epub",
+        "file_size": 1048576,
+        "mime_type": "application/epub+zip",
+        "series": "Tech Series",
+        "series_number": 1,
+        "tags": ["science-fiction", "technology", "ACME CORP."],
+        "publisher": "O'Reilly Media",
+        "contributors": ["John Smith", "ACME CORP."]
+      }
+settings:
+  encodeUrl: true
+  timeout: 0
+  followRedirects: true
+  maxRedirects: 5
+
+docs: |-
+  # Create Media Item
+
+  `POST /api/media-items` — auth: jwt+admin.
+
+  Canonical reference: `docs/developer/api/media-items/create_media_item.md` (docs site → Developer → API). This request is GENERATED from that doc; edit the doc, not this file.