fix: add server-side logging to AI tool routes (#23)

AI routes (remove-background, erase-object, ocr, blur-faces, upscale)
were silently swallowing errors - failures returned HTTP 422 to the
client but never appeared in server logs. This made it impossible for
self-hosters to diagnose issues like 504 timeouts from reverse proxies.

Adds request.log.info() at processing start (tool name, image size, key
settings) and request.log.error() in catch blocks, matching the existing
tool-factory pattern.

Co-authored-by: Siddharth Kumar Sah <siddharth123sk@gmail.com>

apps/api/src/routes/tools/blur-faces.ts

@@ -55,6 +55,15 @@ export function registerBlurFaces(app: FastifyInstance) {
 
     try {
       const settings = settingsRaw ? JSON.parse(settingsRaw) : {};
+      request.log.info(
+        {
+          toolId: "blur-faces",
+          imageSize: fileBuffer.length,
+          blurRadius: settings.blurRadius,
+          sensitivity: settings.sensitivity,
+        },
+        "Starting face blur",
+      );
 
       // Auto-orient to fix EXIF rotation before face detection
       fileBuffer = await autoOrient(fileBuffer);
@@ -111,6 +120,7 @@ export function registerBlurFaces(app: FastifyInstance) {
         faces: result.faces,
       });
     } catch (err) {
+      request.log.error({ err, toolId: "blur-faces" }, "Face blur failed");
       return reply.status(422).send({
         error: "Face blur failed",
         details: err instanceof Error ? err.message : "Unknown error",