Trash icon in the library was firing PATCH /assets/:id with {status:"deleted"}. The PATCH route only accepts display_name/tags/notes so it returned "No fields to update" and the asset stayed put.
* api.js: add deleteAsset(id, {hard}) helper hitting the real DELETE route.
* index.html: deleteAssetPrompt now calls deleteAsset (soft archive). Confirm dialog reworded to match.
* mam-api/routes/assets.js: list endpoint hides status=archived by default. Pass ?include_archived=true to see them in a future restore-from-trash view. Filtering by ?status=archived still works for power users.
* All HTML: bump api.js cache-buster v=4 -> v=5 so the new helper is fetched.
The api.js library-list fix from the previous commit never reached the browser because nginx served all .js with `Cache-Control: public, immutable; max-age=31536000`. The HTML referenced api.js with no version query, so the browser kept its year-cached buggy copy.
* nginx.conf: drop .js from the immutable long-cache block, add a no-cache must-revalidate block so future redeploys are picked up immediately.
* All HTML files: tag api.js refs with ?v=4 so already-running browsers fetch the new version on next page load.
