web: keep a saved photo's look in EXIF and its own row

EXPORT no longer burns the caption strip: the pixels stay the photo's own
and the look travels as metadata — ImageDescription (0x010e) for the tag,
UserComment (0x9286, ASCII header) for the recipe JSON.

SAVE PHOTO now stores the look with the frame (photos.recipe) and the
uploader's consent for the community film strip (photos.consent, PATCH
/api/photos/:id for the owner). The landing reel skips non-consented frames,
and a new MY PHOTOS tab lists the account's saves, reopens one with the
settings it was stored with, and carries the two consent switches.

docker/frontend/src/ui/ToolRail.tsx

@@ -1,15 +1,16 @@
 import type { MsgKey } from '../i18n/vi';
 import { useI18n } from '../i18n/I18nProvider';
 
-// The app's seven tabs. WB leads LIGHT — white balance is the first thing the
+// The app's eight tabs. WB leads LIGHT — white balance is the first thing the
 // eye corrects, and the web rail draws them in the order the panel opens. The
 // rail is a single column on desktop and becomes the bottom bar under 860px
 // (see styles/app.css).
-export type TabId = 'presets' | 'favorited' | 'wb' | 'light' | 'fx' | 'frame' | 'create';
+export type TabId = 'presets' | 'favorited' | 'photos' | 'wb' | 'light' | 'fx' | 'frame' | 'create';
 
 export const TABS: { id: TabId; label: MsgKey; glyph: string }[] = [
   { id: 'presets', label: 'tab.presets', glyph: '◉' },
   { id: 'favorited', label: 'tab.favorited', glyph: '★' },
+  { id: 'photos', label: 'tab.photos', glyph: '▤' },
   { id: 'wb', label: 'tab.wb', glyph: '◐' },
   { id: 'light', label: 'tab.light', glyph: '☀' },
   { id: 'fx', label: 'tab.fx', glyph: '✦' },