web: give each member a photo folder and burn the strip into the export

Every member gets /photos — their own uploads, counted against a 12-photo
cap, each card showing the tagline and the technical line the studio would
print. The studio gains SAVE PHOTO n/12 in the top bar: it renders the full
resolution look, stores the strip (tag/title/meta) with the upload so the
landing reel frames it the same way, and refuses past the cap.

EXPORT now burns that strip into the file: the amber #TAG over the photo's
top-left plus a dark caption band below carrying the recipe name and the
ISO / grain / warmth line. The live preview stays clean, and the saved
upload stays clean too — the reel draws its own frame from the stored
labels, so a burned band would tag the tag twice.

Admins manage any photo through DELETE /api/photos/:id; members only their
own. The users table's photo counts stay in step with the folder.

docker/frontend/src/engine/exportEngine.ts

@@ -68,6 +68,10 @@ export interface RenderOptions {
   frameWindowZoom?: { s: number; u: number; v: number } | null;
   photoRotation?: 0 | 90 | 180 | 270;
   photoStraighten?: number;
+  // The strip the FILE carries: the amber `#TAG` over the photo and a caption
+  // band appended below it, mirroring the landing page's `.lp-shot` +
+  // `.lp-frame-meta`. Left off the live preview, which must not show it.
+  caption?: { tag: string; title: string; meta: string } | null;
 }
 
 export interface RenderInput {
@@ -699,6 +703,55 @@ export async function renderPhoto(input: RenderInput): Promise<RenderResult | nu
         resultImage = sharpened;
       }
     }
+    // 9b. The strip the file carries (export only, never the preview). Drawn
+    // onto a taller surface so every frame variant is treated the same: the
+    // tagline sits on the photo's top-left, the caption band hangs below.
+    const caption = options?.caption ?? null;
+    if (caption) {
+      const W = resultImage.width();
+      const band = Math.round(W * 0.155);
+      const capSurface = createSurface(W, resultImage.height() + band);
+      const loaded = loadFaces(input.assets);
+      if (capSurface && loaded) {
+        own(capSurface);
+        const cc = capSurface.getCanvas();
+        cc.drawImage(resultImage, 0, 0, own(Skia.Paint()));
+
+        const pad = Math.round(W * 0.03);
+        // Amber over a black drop, so the tagline still reads on a bright sky.
+        const tagSize = Math.round(W * 0.026);
+        const tagFont = own(Skia.Font(loaded.typeface, tagSize));
+        const shadow = own(Skia.Paint());
+        shadow.setColor(Skia.Color('#000000'));
+        const amber = own(Skia.Paint());
+        amber.setColor(Skia.Color('#f59e0b'));
+        cc.drawText(caption.tag, pad + 1, pad + tagSize + 1, shadow, tagFont);
+        cc.drawText(caption.tag, pad, pad + tagSize, amber, tagFont);
+
+        const bandTop = resultImage.height();
+        const bandPaint = own(Skia.Paint());
+        bandPaint.setColor(Skia.Color('#0b0b0b'));
+        cc.drawRect(Skia.XYWHRect(0, bandTop, W, band), bandPaint);
+        const titleSize = Math.round(W * 0.042);
+        const metaSize = Math.round(W * 0.026);
+        const titleFont = own(Skia.Font(loaded.typeface, titleSize));
+        const metaFont = own(Skia.Font(loaded.typeface, metaSize));
+        const titlePaint = own(Skia.Paint());
+        titlePaint.setColor(Skia.Color('#f2f2f2'));
+        const metaPaint = own(Skia.Paint());
+        metaPaint.setColor(Skia.Color('#9a9a9a'));
+        cc.drawText(caption.title, pad, bandTop + pad + titleSize, titlePaint, titleFont);
+        cc.drawText(caption.meta, pad, bandTop + pad + titleSize + Math.round(metaSize * 1.7), metaPaint, metaFont);
+
+        flush(capSurface);
+        const composed = own(capSurface.makeImageSnapshot());
+        release(owned, resultImage);
+        resultImage = composed;
+      } else if (capSurface) {
+        capSurface.dispose();
+      }
+    }
+
     let bytes = resultImage.encodeToBytes(Skia.ImageFormat.JPEG, 95);
     if (!bytes || bytes.length === 0) {
       console.error('Failed to encode image to JPEG');