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)

packages/ai/src/background-removal.ts

@@ -20,7 +20,8 @@ export async function removeBackground(
   const inputPath = join(tmpdir(), `rembg_in_${id}.png`);
   const outputPath = join(outputDir, `rembg_out_${id}.png`);
 
-  await writeFile(inputPath, inputBuffer);
+  const pngBuffer = await sharp(inputBuffer).png().toBuffer();
+  await writeFile(inputPath, pngBuffer);
   try {
     const meta = await sharp(inputBuffer).metadata();
     const megapixels = ((meta.width ?? 0) * (meta.height ?? 0)) / 1_000_000;

packages/ai/src/colorization.ts

@@ -1,5 +1,6 @@
 import { readFile, writeFile } from "node:fs/promises";
 import { join } from "node:path";
+import sharp from "sharp";
 import { type ProgressCallback, parseStdoutJson, runPythonWithProgress } from "./bridge.js";
 
 export interface ColorizeOptions {
@@ -23,7 +24,8 @@ export async function colorize(
   const inputPath = join(outputDir, "input_colorize.png");
   const outputPath = join(outputDir, "output_colorize.png");
 
-  await writeFile(inputPath, inputBuffer);
+  const pngBuffer = await sharp(inputBuffer).png().toBuffer();
+  await writeFile(inputPath, pngBuffer);
   const { stdout } = await runPythonWithProgress(
     "colorize.py",
     [inputPath, outputPath, JSON.stringify(options)],

packages/ai/src/face-enhancement.ts

@@ -1,5 +1,6 @@
 import { readFile, writeFile } from "node:fs/promises";
 import { join } from "node:path";
+import sharp from "sharp";
 import { type ProgressCallback, parseStdoutJson, runPythonWithProgress } from "./bridge.js";
 
 export interface EnhanceFacesOptions {
@@ -25,7 +26,8 @@ export async function enhanceFaces(
   const inputPath = join(outputDir, "input_enhance_faces.png");
   const outputPath = join(outputDir, "output_enhance_faces.png");
 
-  await writeFile(inputPath, inputBuffer);
+  const pngBuffer = await sharp(inputBuffer).png().toBuffer();
+  await writeFile(inputPath, pngBuffer);
   const { stdout } = await runPythonWithProgress(
     "enhance_faces.py",
     [inputPath, outputPath, JSON.stringify(options)],

packages/ai/src/inpainting.ts

@@ -1,5 +1,6 @@
 import { readFile, writeFile } from "node:fs/promises";
 import { join } from "node:path";
+import sharp from "sharp";
 import { type ProgressCallback, parseStdoutJson, runPythonWithProgress } from "./bridge.js";
 
 export async function inpaint(
@@ -12,8 +13,10 @@ export async function inpaint(
   const maskPath = join(outputDir, "mask_inpaint.png");
   const outputPath = join(outputDir, "output_inpaint.png");
 
-  await writeFile(inputPath, inputBuffer);
-  await writeFile(maskPath, maskBuffer);
+  const pngInput = await sharp(inputBuffer).png().toBuffer();
+  const pngMask = await sharp(maskBuffer).png().toBuffer();
+  await writeFile(inputPath, pngInput);
+  await writeFile(maskPath, pngMask);
 
   const { stdout } = await runPythonWithProgress("inpaint.py", [inputPath, maskPath, outputPath], {
     onProgress,

packages/ai/src/noise-removal.ts

@@ -1,5 +1,6 @@
 import { readFile, writeFile } from "node:fs/promises";
 import { join } from "node:path";
+import sharp from "sharp";
 import { type ProgressCallback, parseStdoutJson, runPythonWithProgress } from "./bridge.js";
 
 export interface NoiseRemovalOptions {
@@ -28,7 +29,8 @@ export async function noiseRemoval(
   const inputPath = join(outputDir, "input_denoise.png");
   const outputPath = join(outputDir, "output_denoise.png");
 
-  await writeFile(inputPath, inputBuffer);
+  const pngBuffer = await sharp(inputBuffer).png().toBuffer();
+  await writeFile(inputPath, pngBuffer);
   const { stdout } = await runPythonWithProgress(
     "noise_removal.py",
     [inputPath, outputPath, JSON.stringify(options)],

packages/ai/src/restoration.ts

@@ -1,5 +1,6 @@
 import { readFile, writeFile } from "node:fs/promises";
 import { join } from "node:path";
+import sharp from "sharp";
 import { type ProgressCallback, parseStdoutJson, runPythonWithProgress } from "./bridge.js";
 
 export interface RestorePhotoOptions {
@@ -32,7 +33,8 @@ export async function restorePhoto(
   const inputPath = join(outputDir, "input_restore.png");
   const outputPath = join(outputDir, "output_restore.png");
 
-  await writeFile(inputPath, inputBuffer);
+  const pngBuffer = await sharp(inputBuffer).png().toBuffer();
+  await writeFile(inputPath, pngBuffer);
   const { stdout } = await runPythonWithProgress(
     "restore.py",
     [inputPath, outputPath, JSON.stringify(options)],

packages/ai/src/upscaling.ts

@@ -1,5 +1,6 @@
 import { readFile, writeFile } from "node:fs/promises";
 import { join } from "node:path";
+import sharp from "sharp";
 import { type ProgressCallback, parseStdoutJson, runPythonWithProgress } from "./bridge.js";
 
 export interface UpscaleOptions {
@@ -28,7 +29,8 @@ export async function upscale(
   const inputPath = join(outputDir, "input_upscale.png");
   const outputPath = join(outputDir, "output_upscale.png");
 
-  await writeFile(inputPath, inputBuffer);
+  const pngBuffer = await sharp(inputBuffer).png().toBuffer();
+  await writeFile(inputPath, pngBuffer);
   const { stdout } = await runPythonWithProgress(
     "upscale.py",
     [inputPath, outputPath, JSON.stringify(options)],