feat: @gsc/web-kit v0.1.0 — Phase 1 scaffold

The kit. Drop into any GSC Next.js frontend; everything that's not
domain content lives here. Wraps @limitless/ui primitives with the
app-shaped patterns we keep reimplementing: layout, auth, data
display, forms, feedback, navigation.

Phase 1 ships the package skeleton:

- package.json with 14 sub-exports (./layout · ./auth · ./auth/server
  · ./auth/middleware · ./shell · ./shell/server · ./data · ./forms ·
  ./feedback · ./navigation · ./api · ./utils + the root and ./css).
- Empty module stubs so the import map resolves while later phases
  fill in real surface area.
- Canonical CSS bundle at @gsc/web-kit/css — all.min.css +
  sidebar-overrides.css + the seven layout-3 background images,
  copied from chronos and committed in one place so no app has to
  ship the 1MB sidecar on its own anymore.
- tsc-based build + a postbuild script that mirrors @limitless/ui:
  emits .js + .d.ts, copies styles/, rewrites bare ESM imports to
  include .js extensions.
- Peer deps on next, react, react-dom, bootstrap.
- Hard deps on @limitless/ui (file: dep), next-auth, next-intl, zod.

Build verified: tsc emits, all 14 export paths resolve under dist/.
No functional code yet — Phase 2 lands AppLayout / createAuth /
fetchShellConfig and the gscCRM pilot cuts over.

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

src/auth/index.ts

@@ -0,0 +1,2 @@
+// @gsc/web-kit/auth — Phase 1 stub. Real surface lands in later phases.
+export {};