Strip template artifacts and fix lint errors

Remove npm lockfile, unused create-next-app SVGs, project-specific
next.config workarounds, and the unused @remixicon/react and date-fns deps.

Replace three set-state-in-effect patterns with useSyncExternalStore in
use-mobile, DialogPortal, and Carousel; the carousel change also fixes a
leaked reInit listener. yarn lint and yarn build are clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01K8PmydbW6A1S2Tw3SFc3Cg

tsconfig.json

@@ -15,7 +15,7 @@
     "moduleResolution": "bundler",
     "resolveJsonModule": true,
     "isolatedModules": true,
-    "jsx": "preserve",
+    "jsx": "react-jsx",
     "incremental": true,
     "plugins": [
       {
@@ -32,7 +32,8 @@
     "next-env.d.ts",
     "**/*.ts",
     "**/*.tsx",
-    ".next/types/**/*.ts"
+    ".next/types/**/*.ts",
+    ".next/dev/types/**/*.ts"
   ],
   "exclude": [
     "node_modules"