feat(application): PSD layer separation and image quality/count threading

Convert GPT Image 2 layered PSD output into canvas image/text nodes with a
local separation fallback (new layer_separation.go, oov/psd dependency),
default layer-separation/edit-elements output_format to psd, and thread
imageQuality/imageCount through project generation and job processing.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

server/go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/hibiken/asynq v0.26.0
 	github.com/jackc/pgx/v5 v5.8.0
 	github.com/minio/minio-go/v7 v7.2.1
+	github.com/oov/psd v0.0.0-20260122084234-c463b6a89e2f
 	github.com/redis/go-redis/v9 v9.19.0
 	github.com/sky-valley/pi v0.2.8
 	github.com/yalue/onnxruntime_go v1.22.0
@@ -28,6 +29,7 @@ require (
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/golang-jwt/jwt/v4 v4.5.2 // indirect
+	github.com/gopherjs/gopherjs v1.21.0 // indirect
 	github.com/grafana/pyroscope-go v1.3.0 // indirect
 	github.com/grafana/pyroscope-go/godeltaprof v0.1.10 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.7 // indirect