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/nanoid/non-secure/index.js

@@ -0,0 +1,21 @@
+let urlAlphabet =
+  'useandom-26T198340PX75pxJACKVERYMINDBUSHWOLF_GQZbfghjklqvwyzrict'
+let customAlphabet = (alphabet, defaultSize = 21) => {
+  return (size = defaultSize) => {
+    let id = ''
+    let i = size | 0
+    while (i--) {
+      id += alphabet[(Math.random() * alphabet.length) | 0]
+    }
+    return id
+  }
+}
+let nanoid = (size = 21) => {
+  let id = ''
+  let i = size | 0
+  while (i--) {
+    id += urlAlphabet[(Math.random() * 64) | 0]
+  }
+  return id
+}
+export { nanoid, customAlphabet }