site: dev /api/edit-find-tag/ middleware + register timelined hero

Adds the Vite-middleware backend that the refactored FindCard tag picker
POSTs to (writes editorialTags into find frontmatter). Without it the
in-card tag toggles 404 in dev. Also registers timelined's hero in the
heroes map so it shows up on the home grid.

src/lib/hero.ts

@@ -9,6 +9,7 @@ import hyperkey from '../content/reviews/hyperkey/hero.png';
 import ice from '../content/reviews/ice/ice-bar.png';
 import macMouseFix from '../content/reviews/mac-mouse-fix/studio-display.png';
 import superkey from '../content/reviews/superkey/hero.jpg';
+import timelined from '../content/reviews/timelined/hero.png';
 import tot from '../content/reviews/tot/seven-dots.png';
 
 import antinote from '../content/reviews/antinote/swipe.mp4';
@@ -34,6 +35,7 @@ export const heroes: Record<string, Hero | undefined> = {
   ice: { kind: 'image', src: ice },
   'mac-mouse-fix': { kind: 'image', src: macMouseFix },
   superkey: { kind: 'image', src: superkey },
+  timelined: { kind: 'image', src: timelined },
   tot: { kind: 'image', src: tot },
   antinote: { kind: 'video', src: antinote },
   cotypist: { kind: 'video', src: cotypist },