feat: v0.3.0 — Phase 3/4 façades + AppLayout on AppShell

- Curated re-exports from @limitless/ui through /forms, /data,
  /feedback, /navigation, /utils sub-paths so apps stop importing
  from the lower layer.
- /forms also re-exports the full @limitless/ui validation surface
  (hooks, format/security/address validators, types).
- AppLayout is now a thin wrapper over @limitless/ui's <AppShell> —
  same ShellConfig DTO, no duplicated chrome code.
- shell/types + shell/index re-export from @limitless/ui to keep one
  canonical type and one shared context.
- auth middleware: loose NextRequestLike typing to avoid two-copies-
  of-next conflict with the consumer's next.
- postbuild: rewrite ../images/ to ./images/ in copied CSS so refs
  resolve in dist/styles/.

Widget family in /data is the intersection of limitless's two
Widget files (Widget.d.ts vs Widget/index.d.ts collision in dist);
upstream fix needed before exposing IconWidget/UserWidget/etc.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/postbuild.cjs

@@ -25,6 +25,18 @@ function copyDir(src, dst) {
 }
 if (fs.existsSync(srcStyles)) {
   copyDir(srcStyles, distStyles);
+
+  // Rewrite ../images/... references in any copied CSS to ./images/...
+  // The source CSS assumes a sibling src/images/ dir; in dist/ the images
+  // live at dist/styles/images/ alongside the CSS, so the relative path
+  // is one level shorter.
+  for (const f of fs.readdirSync(distStyles)) {
+    if (!f.endsWith(".css")) continue;
+    const p = path.join(distStyles, f);
+    const c = fs.readFileSync(p, "utf8");
+    const fixed = c.replace(/\.\.\/images\//g, "./images/");
+    if (fixed !== c) fs.writeFileSync(p, fixed);
+  }
 }
 
 // 2. Fix ESM relative imports: append `.js` to bare specifiers like