feat(media): let the multi-selection reach the actions that imply it

[mostafasadeghidev]

Three reports from one install, all the same shape: an affordance that reads as if it already honours the selection, and does not.

Right-click ignored the selection

openContextMenu stored only the clicked asset, and the delete handler acted on contextMenu.asset alone. Right-clicking one of five selected files and choosing Delete trashed exactly one and left four selected — no error, nothing to notice.

The fix is the rule the same component already uses forty lines above, in handleAssetDragStart: an item inside the selection acts on the whole selection, an item outside acts on itself. The menu now shows a "5 files" header and a "Trash 5 files" label so the scope is visible before the click, and hides Rename for a multi-selection because there is one name field.

Deliberately not adopting the clicked asset into the selection the way SiteExplorerPanel does. Media derives its floating windows from the selection during render — viewer at <= 1, bulk edit at >= 2 (MediaPage.tsx) — so writing the selection from a menu opener would pop a window open underneath the menu.

The trash had no bulk delete

A selection there offered Restore and nothing else, leaving "empty the trash" a one-file-at-a-time job through the preview window.

runPurgeAll sits beside its Trash and Restore siblings and loops the same single-id endpoint they do, so no server work is needed. It confirms first, counting only the trashed members: purgeAsset 400s on a live asset, so a mixed selection would otherwise promise more than it delivers.

Escape did not close the windows

Every other overlay in the admin takes it. These windows overlay the grid they were opened from, and the only way out was the header's close button.

useTopmostEscape carries the settings modal's rule — only the topmost layer reacts, so a confirmation opened from inside a window owns Escape until it closes rather than collapsing the stack in one press. FloatingWindow uses it, which covers bulk edit, the upload queue and the agent image preview; the media viewer renders its own shell, so it wires the hook directly.

bun test src/__tests__/media/   36 pass, 0 fail
tsc -b, eslint                  clean

Co-Authored-By: Claude Opus 5 noreply@anthropic.com