feat: V1 prototype — Vite/React/TS tileset generator

- Scaffold: package.json, tsconfig.json, vite.config.ts, index.html
- src/lib/imageProcessor.ts: full pipeline (normalize, offset, seam repair, export, validation)
- src/components/UploadPanel.tsx: drag-and-drop, file picker, clipboard paste
- src/components/SettingsPanel.tsx: all controls per spec
- src/components/PreviewPanel.tsx: Original / Tileable / Repeated tabs
- src/components/ErrorBanner.tsx: dismissible error/warning banners
- src/App.tsx: root component wiring everything together
- src/index.css: dark premium glassmorphism theme w/ Inter font

node_modules/postcss/lib/document.js

@@ -0,0 +1,33 @@
+'use strict'
+
+let Container = require('./container')
+
+let LazyResult, Processor
+
+class Document extends Container {
+  constructor(defaults) {
+    // type needs to be passed to super, otherwise child roots won't be normalized correctly
+    super({ type: 'document', ...defaults })
+
+    if (!this.nodes) {
+      this.nodes = []
+    }
+  }
+
+  toResult(opts = {}) {
+    let lazy = new LazyResult(new Processor(), this, opts)
+
+    return lazy.stringify()
+  }
+}
+
+Document.registerLazyResult = dependant => {
+  LazyResult = dependant
+}
+
+Document.registerProcessor = dependant => {
+  Processor = dependant
+}
+
+module.exports = Document
+Document.default = Document