fix(analysis): cap OCR decoded pixels to stop decompression-bomb OOM

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/src/settings.rs

@@ -473,6 +473,8 @@ impl AnalysisSettings {
             backend: base.backend,
             ocr_detection_model: base.ocr_detection_model.clone(),
             ocr_recognition_model: base.ocr_recognition_model.clone(),
+            // Env-only decompression-bomb decode cap, carried from the base.
+            ocr_max_decode_pixels: base.ocr_max_decode_pixels,
         })
     }
 }