Initial commit: img-infinite-canvas AI design workbench MVP

Moteva-style AI design workbench replica. Home prompt creates a project;
the project page provides an infinite canvas with node drag, zoom/pan,
a design chat panel, history replay, image asset upload, and project
save/regenerate.

- Backend: go-zero, DDD layering, sqlc/pgx, optional PostgreSQL; memory
  or Redis cache; asynq job queue; MinIO/S3/R2/OSS object storage;
  sky-valley/pi agent runtime adapter.
- Frontend: Next.js App Router + Vite artifact build, TypeScript, i18n,
  shadcn/ui components, auth (OTP/Turnstile/Google/WeChat).
- Deploy: Docker Compose and k3s manifests.

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

server/internal/domain/design/text_extraction.go

@@ -0,0 +1,39 @@
+package design
+
+import "context"
+
+type TextExtractionRequest struct {
+	ImageURL string
+	Prompt   string
+	Width    float64
+	Height   float64
+}
+
+type ExtractedTextLayer struct {
+	Text          string
+	OriginalText  string
+	X             float64
+	Y             float64
+	Width         float64
+	Height        float64
+	FontSize      float64
+	FontFamily    string
+	FontWeight    string
+	Color         string
+	TextAlign     string
+	LineHeight    float64
+	LetterSpacing float64
+	StrokeColor   string
+	StrokeWidth   float64
+	Opacity       float64
+	Rotation      float64
+	Confidence    float64
+}
+
+type TextExtraction struct {
+	Layers []ExtractedTextLayer
+}
+
+type TextExtractor interface {
+	ExtractText(ctx context.Context, req TextExtractionRequest) (TextExtraction, error)
+}