chore: update README and package.json with project info

- Replace scaffold README with project-specific documentation
- Rename package to fitlabs.dev, bump to v1.0.0

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package.json

@@ -1,7 +1,7 @@
 {
-  "name": "fitlabs-scaffold",
+  "name": "fitlabs.dev",
   "type": "module",
-  "version": "0.0.1",
+  "version": "1.0.0",
   "engines": {
     "node": ">=22.12.0"
   },