fix: format preservation, dispatcher stability, and health reporting

Closes #17, #18, #19, #31, #32, #33, #34

Format preservation (#17, #18, #19):
- Add resolveOutputFormat to rotate, resize, text-overlay, watermark-text,
  border, replace-color, blur-faces, upscale, erase-object, restore-photo
- Alpha-aware fallback: border with corner radius/shadow and replace-color
  with makeTransparent fall back to PNG for non-alpha formats (JPEG)
- Python sidecar tools (blur-faces, upscale, erase-object) now convert
  PNG output back to input format, matching restore-photo/colorize pattern
- Upscale and erase-object default to "auto" format detection instead of PNG

Dispatcher stability (#31, #32):
- Add gc.collect() and torch.cuda.empty_cache() after each dispatcher request
- Add configurable max_requests (default 50) for periodic dispatcher restart
- Add exponential backoff to dispatcher crash recovery in bridge.ts
- Circuit breaker: 5 crashes within 60s permanently disables dispatcher
- Reset crash counter on successful dispatcher startup

Health & security (#33, #34):
- Export getDispatcherStatus() from @snapotter/ai with running/ready/failed/
  gpu/pid/consecutiveCrashes fields
- Admin health endpoint now includes full dispatcher status
- Add pip-audit job to CI workflow for Python dependency scanning

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

@@ -239,8 +239,20 @@ export function registerRestorePhoto(app: FastifyInstance) {
         denoiseStrength: s.denoiseStrength,
         colorize: s.colorize,
       });
-      const outputFilename = `${filename.replace(/\.[^.]+$/, "")}_restored.png`;
-      return { buffer: result.buffer, filename: outputFilename, contentType: "image/png" };
+      const outputFormat = await resolveOutputFormat(inputBuffer, filename);
+      let outputBuffer = result.buffer;
+      if (outputFormat.format !== "png") {
+        outputBuffer = await sharp(result.buffer)
+          .toFormat(outputFormat.format, { quality: outputFormat.quality })
+          .toBuffer();
+      }
+      const ext = outputFormat.format === "jpeg" ? "jpg" : outputFormat.format;
+      const outputFilename = `${filename.replace(/\.[^.]+$/, "")}_restored.${ext}`;
+      return {
+        buffer: outputBuffer,
+        filename: outputFilename,
+        contentType: outputFormat.contentType,
+      };
     },
   });
 }