fix(bruno): convert drifted body keys to body.data — CLI scenario runs now carry bodies

Follow-up to the sweep route audit, correcting its diagnosis: the CLI
DOES read .yml bodies — via OpenCollection's `body.data` string form
(the NewDevDBSetup script always worked because it used it). The
failing scenario POSTs used `body.json` (structured) / `body.jsonBody`
(string) — keys the CLI silently ignores, sending Content-Length: 0
with form-urlencoded content-type, so every server bind failed.

- 81 bodies converted to data-form (json maps serialized; jsonBody
  strings kept verbatim, {{vars}} intact).
- 6 pre-existing TRUNCATED payloads repaired: the original generator
  cut bodies at the first {{var}} (every SHA-256-identified scenario
  plus Sync Progress/Sync Bookmarks shipped mid-JSON and 400'd from
  day one). Rewritten whole, faithful to each file's documented
  purpose; book_sha256/book_uuid added to the environment.
- environments: opds_base_url correction from the sweep retained.

Verified live against the rebuilt dev container: the full koreader
scenario tree runs green through `bru run` — 14/14 (202s across
immediate/checkpoint/SHA-256 progress, 200s bookmarks, highlights,
notes; SHA-256 book identification exercised against a real
file_sha256).

bruno/devices/koreader/scenarios/Checkpoint Sync.yml

@@ -3,18 +3,8 @@ docs: "## Checkpoint Sync\n\nIncremental sync using checkpoint-based change trac
   \ Repeat from step 3\n\n**Sync Optimization:**\n- Only books with progress changes\n- Skips unmodified books\n- Delta transfer\n- Compression for large payloads\n- Batch processing\n\n**Failure Handling:**\n- Checkpoint ID preserved on failure\n- Retry with same checkpoint\n- Full sync if checkpoint expired\n- Checkpoint validity: 24 hours\n- Auto-fallback to full sync\n\n**Performance:**\n- Small changes (1-10 books): 100-300ms\n- Medium changes (10-50 books): 300ms-1s\n- Large changes (50-100 books): 1-3s\n- Typical: 5-10x faster than full sync\n\n**When to Use:**\n- Default sync mode for most users\n- Periodic background sync\n- Large library management\n- Mobile/network-constrained environments\n- Battery-powered devices\n\n**Configuration:**\n- Checkpoint expiration: 24 hours\n- Max history: 100 checkpoints\n- Auto-cleanup of old checkpoints\n- Configurable sync interval"
 http:
   body:
-    json:
-      books:
-      - chapter: 3
-        percentage: 0.45
-        uuid: '{{media_item_id}}'
-      - chapter: 8
-        percentage: 0.75
-        uuid: '{{media_item_id}}'
-      checkpoint_id: checkpoint-uuid
-      since_timestamp: '2026-01-30T19:00:00Z'
-      sync_mode: checkpoint
     type: json
+    data: "{\n  \"books\": [\n    {\n      \"chapter\": 3,\n      \"percentage\": 0.45,\n      \"uuid\": \"{{media_item_id}}\"\n    },\n    {\n      \"chapter\": 8,\n      \"percentage\": 0.75,\n      \"uuid\": \"{{media_item_id}}\"\n    }\n  ],\n  \"checkpoint_id\": \"checkpoint-uuid\",\n  \"since_timestamp\": \"2026-01-30T19:00:00Z\",\n  \"sync_mode\": \"checkpoint\"\n}"
   headers:
   - key: Content-Type
     value: application/json