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/json5/lib/util.js

@@ -0,0 +1,35 @@
+const unicode = require('../lib/unicode')
+
+module.exports = {
+    isSpaceSeparator (c) {
+        return typeof c === 'string' && unicode.Space_Separator.test(c)
+    },
+
+    isIdStartChar (c) {
+        return typeof c === 'string' && (
+            (c >= 'a' && c <= 'z') ||
+        (c >= 'A' && c <= 'Z') ||
+        (c === '$') || (c === '_') ||
+        unicode.ID_Start.test(c)
+        )
+    },
+
+    isIdContinueChar (c) {
+        return typeof c === 'string' && (
+            (c >= 'a' && c <= 'z') ||
+        (c >= 'A' && c <= 'Z') ||
+        (c >= '0' && c <= '9') ||
+        (c === '$') || (c === '_') ||
+        (c === '\u200C') || (c === '\u200D') ||
+        unicode.ID_Continue.test(c)
+        )
+    },
+
+    isDigit (c) {
+        return typeof c === 'string' && /[0-9]/.test(c)
+    },
+
+    isHexDigit (c) {
+        return typeof c === 'string' && /[0-9A-Fa-f]/.test(c)
+    },
+}