Prevent image expansion and detail hallucination in relighting

Add explicit constraints to prevent AI model from:
- Extending/outpainting beyond original image boundaries
- Hallucinating details not visible in source (closed eyes, hidden areas)

src/utils/lighting.ts

@@ -344,6 +344,8 @@ export function buildOptimizedLightingPrompt(
     "Only change illumination: light direction, brightness, color temperature, shadows, highlights, reflections, and ambient lighting mood required by the lighting plan.",
     "Treat any preset or style wording as a lighting reference only, not permission to redesign the person, outfit, background, pose, scene, or photographic composition.",
     "Do not add or remove people or objects, do not beautify or re-age the person, do not replace the face, do not change hairstyle or clothing, do not crop the subject, and do not create a different scene.",
+    "Do not hallucinate, invent, or complete any details that are not visible in the source image — if eyes, features, or areas are hidden, closed, covered, or obscured in the original, they must remain exactly as they are. Only adjust how light and shadow fall on the existing content.",
+    "Do NOT extend, expand, outpaint, or add any content outside the original image boundaries. The output must have the exact same frame, dimensions, and edge content as the source image — every edge pixel must match the original.",
   ];
 
   // 打光参考图：第二张图片是打光参考，分析其光照风格应用到原图