修复了一点bug，然后增加了图层拆分更多的功能

contracts/http/route-surface.v1.json

@@ -48,6 +48,8 @@
     { "method": "DELETE", "path": "/api/image-templates/{id}" },
     { "method": "PATCH", "path": "/api/image-templates/{id}" },
     { "method": "POST", "path": "/api/internal/worker/tick" },
+    { "method": "GET", "path": "/api/layer-compositions/{id}" },
+    { "method": "PUT", "path": "/api/layer-compositions/{id}" },
     { "method": "DELETE", "path": "/api/logs" },
     { "method": "GET", "path": "/api/logs" },
     { "method": "POST", "path": "/api/prompt/assemble" },