Add i18n factory + AdminShell My Profile + LogoutButton anchor

- src/i18n/server.ts: createI18nConfig factory consolidating the locale
  resolution chain (cookie → access_token preferred_language claim →
  Accept-Language → default). Reusable across apps; previously each
  frontend reimplemented it.
- AdminShell: thread signoutPath + myProfileUrl (default
  https://my.gosec.internal/profile) into the navbar; render My Profile
  link alongside logout.
- LogoutButton: replace two-step fetch+signOut+redirect with a plain
  anchor pointing at signoutPath — the NextAuth POST-only signout
  endpoint plus form-CSRF flow doesn't need client JS.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@gsc/web-kit",
-  "version": "0.4.1",
+  "version": "0.5.1",
   "description": "GSC web app skeleton — layout, auth, data, forms, feedback, navigation, chrome. Built on @limitless/ui. Drop into a Next.js app and just write pages.",
   "license": "MIT",
   "type": "module",
@@ -65,6 +65,14 @@
       "types": "./dist/api/index.d.ts",
       "import": "./dist/api/index.js"
     },
+    "./i18n": {
+      "types": "./dist/i18n/index.d.ts",
+      "import": "./dist/i18n/index.js"
+    },
+    "./i18n/server": {
+      "types": "./dist/i18n/server.d.ts",
+      "import": "./dist/i18n/server.js"
+    },
     "./utils": {
       "types": "./dist/utils/index.d.ts",
       "import": "./dist/utils/index.js"