fix: clip pad ±3s + OSD-clock alignment at cut points (single-frame OCR)

CHANGELOG.md

@@ -32,6 +32,8 @@ version tags are cut in this repo — POC stage, `main` is the release line).
 - History `Klip` button → office-only `GET /api/batch-clip/<date>/<batch_number>`
   trims+concatenates motionEye recordings to the batch window (`src/clip.py`),
   download `b<n>-<date>-<HH-MM-SS>.mp4`.
+  - `MOTIONEYE_CLIP_PAD` (default ±3 s window padding) + OSD-clock alignment via
+    single-frame OCR at each cut point (`MOTIONEYE_OSD_ALIGN`, default on).
 
 ### Changed
 - OCR engine default **`rapid`** (was `tesseract`) across `config.yaml`,