## Release v0.51.244 — Release HL (stage-q16)
UX-approved direction via Telegram (workspace drag-drop polish you requested). All 4 drag-drop flows verified live in-browser.
### Added
| PR | Author | Feature |
|----|--------|---------|
| #3402 / #3424 | @pamnard | **Drop OS files/folders onto a specific workspace folder row or breadcrumb** to upload into that directory (not just the current dir). OS folder drops are traversed (`webkitGetAsEntry`/`readEntries`) preserving nested structure. Uploads via the existing `/api/workspace/upload` (no new backend). |
### Fixed
- **Composer drop-zone jank**: dragging a workspace file (or OS file) over the composer footer rendered a translucent overlay that let the textarea/chips/icons bleed through and collide with the hint text. Now a clean, fully-opaque box with a single centered **context-aware** label — *"Drop to insert workspace reference"* (workspace file → `@path` insert) vs *"Drop files to attach"* (OS file → message attach).
- **Drag-drop handler coexistence (CORE, caught in review)**: #3424's OS-upload binding assigned `el.ondrop` on folder rows, which **overwrote** the drag-to-move handler from #3422 (also `el.ondrop`) — silently breaking move-to-folder (the ws-path drop fell through to the composer as an `@path` insert). Fixed by binding the OS-upload handlers via `addEventListener` so they compose; each handler gates on its own drag type.
### Drag-drop matrix — all verified LIVE in-browser (real drag→drop, asserted on disk)
| Flow | Result |
|------|--------|
| OS image → composer footer | ✓ attaches |
| workspace file → composer footer | ✓ inserts `@path` |
| workspace file → workspace folder | ✓ moves on disk (report.md → docs/) |
| OS file → workspace folder | ✓ uploads into target folder |
### Scope note
#3424's PR branch carried the OLD pre-hardening `_handle_file_move`. Applied **frontend-only** — master's hardened move backend (v0.51.243, TOCTOU/symlink fixes) is untouched (Codex confirmed no `api/routes.py` diff).
### Gate
- Full pytest suite: **7542 passed, 9 skipped, 3 xpassed, 0 failed**
- ESLint: CLEAN · ruff: CLEAN · browser-smoke: CLEAN
- Codex (regression): CORE handler-clobber → fixed → **SAFE TO SHIP**
Co-authored-by: pamnard <pamnard@users.noreply.github.com>
