fix: AVIF sidecar crash, edit-metadata silent no-op, passport batch blank images, color-palette hex overflow, OCR log noise

- Convert all AI bridge inputs to PNG before writing to disk so PIL can
  read AVIF/WebP/TIFF (7 bridge files; face-detection and OCR already
  had this pattern)
- Add title/author aliases to edit-metadata schema so common field names
  actually write EXIF tags instead of being silently stripped by Zod
- Port extend/pad crop logic from passport-photo single endpoint to the
  batch pipeline so crop regions extending beyond the image get filled
  with background color instead of producing all-white output
- Clamp quantized color channels to 255 in color-palette to prevent
  Math.round(255/16)*16=256 from producing invalid hex like #100100100
- Compare OCR fallback warning against expected engine name per tier
  instead of comparing engine name against tier name (always mismatch)

apps/api/src/routes/tools/passport-photo.ts

@@ -560,11 +560,18 @@ export function registerPassportPhoto(app: FastifyInstance) {
       const docSpec = countrySpec.documents.find((d) => d.type === s.documentType);
       if (!docSpec) throw new Error(`No ${s.documentType} spec for ${s.countryCode}`);
 
-      // Convert normalized landmarks (0-1) to pixel coordinates
-      const crownYPx = (landmarks.crown.y + s.adjustY) * imgH;
-      const chinYPx = (landmarks.chin.y + s.adjustY) * imgH;
-      const eyeYPx = (landmarks.eyeCenter.y + s.adjustY) * imgH;
-      const faceCenterXPx = (landmarks.faceCenterX + s.adjustX) * imgW;
+      // Use actual bg-removed image dimensions (may differ from original)
+      const bgRemovedMeta = await sharp(bgRemovedBuffer).metadata();
+      const actualW = bgRemovedMeta.width ?? imgW;
+      const actualH = bgRemovedMeta.height ?? imgH;
+      const scaleX = actualW / imgW;
+      const scaleY = actualH / imgH;
+
+      // Convert normalized landmarks (0-1) to pixel coordinates in bg-removed space
+      const crownYPx = (landmarks.crown.y + s.adjustY) * imgH * scaleY;
+      const chinYPx = (landmarks.chin.y + s.adjustY) * imgH * scaleY;
+      const eyeYPx = (landmarks.eyeCenter.y + s.adjustY) * imgH * scaleY;
+      const faceCenterXPx = (landmarks.faceCenterX + s.adjustX) * imgW * scaleX;
 
       const targetHeadRatio = (docSpec.headHeightMin + docSpec.headHeightMax) / 2;
       const headHeightPx = chinYPx - crownYPx;
@@ -575,40 +582,58 @@ export function registerPassportPhoto(app: FastifyInstance) {
       const topY = eyeYPx - photoHeightPx * (1 - docSpec.eyeLineFromBottom);
       const leftX = faceCenterXPx - photoWidthPx / 2;
 
-      const cropW = Math.min(Math.round(photoWidthPx), imgW);
-      const cropH = Math.min(Math.round(photoHeightPx), imgH);
-      let cropLeft = Math.max(0, Math.round(leftX));
-      let cropTop = Math.max(0, Math.round(topY));
-      if (cropLeft + cropW > imgW) cropLeft = imgW - cropW;
-      if (cropTop + cropH > imgH) cropTop = imgH - cropH;
-      cropLeft = Math.max(0, cropLeft);
-      cropTop = Math.max(0, cropTop);
-
       // Composite onto background
       const hex = s.bgColor.replace("#", "");
       const bgR = Number.parseInt(hex.slice(0, 2), 16);
       const bgG = Number.parseInt(hex.slice(2, 4), 16);
       const bgB = Number.parseInt(hex.slice(4, 6), 16);
+      const bgRgb = { r: bgR, g: bgG, b: bgB, alpha: 1 };
 
-      const bgRemovedMeta = await sharp(bgRemovedBuffer).metadata();
       const bgLayer = await sharp({
         create: {
-          width: bgRemovedMeta.width ?? imgW,
-          height: bgRemovedMeta.height ?? imgH,
+          width: actualW,
+          height: actualH,
           channels: 4,
-          background: { r: bgR, g: bgG, b: bgB, alpha: 1 },
+          background: bgRgb,
         },
       })
         .composite([{ input: bgRemovedBuffer, blend: "over" }])
         .png()
         .toBuffer();
 
+      // Pad instead of clamp so the crop region can extend beyond the image
+      const rawLeft = Math.round(leftX);
+      const rawTop = Math.round(topY);
+      const rawW = Math.round(photoWidthPx);
+      const rawH = Math.round(photoHeightPx);
+
+      const padLeft = Math.max(0, -rawLeft);
+      const padTop = Math.max(0, -rawTop);
+      const padRight = Math.max(0, rawLeft + rawW - actualW);
+      const padBottom = Math.max(0, rawTop + rawH - actualH);
+
+      let sourceForCrop = bgLayer;
+      if (padLeft > 0 || padTop > 0 || padRight > 0 || padBottom > 0) {
+        sourceForCrop = await sharp(bgLayer)
+          .extend({
+            top: padTop,
+            bottom: padBottom,
+            left: padLeft,
+            right: padRight,
+            background: bgRgb,
+          })
+          .toBuffer();
+      }
+
+      const cropLeft = rawLeft + padLeft;
+      const cropTop = rawTop + padTop;
+
       const MM_PER_INCH = 25.4;
       const targetWidthPx = Math.round((docSpec.width / MM_PER_INCH) * docSpec.dpi);
       const targetHeightPx = Math.round((docSpec.height / MM_PER_INCH) * docSpec.dpi);
 
-      const result = await sharp(bgLayer)
-        .extract({ left: cropLeft, top: cropTop, width: cropW, height: cropH })
+      const result = await sharp(sourceForCrop)
+        .extract({ left: cropLeft, top: cropTop, width: rawW, height: rawH })
         .resize(targetWidthPx, targetHeightPx, { fit: "fill" })
         .jpeg({ quality: 95 })
         .toBuffer();