chore: migrate from ESLint/Prettier to Biome

- Add biome.json with recommended preset + custom rules
- Remove eslint.config.mjs (root, apps/react, apps/elysia)
- Remove .prettierrc and .prettierignore
- Update package.json: remove eslint/prettier deps, add biome scripts
- Update Makefile: lint/format targets to biome
- Update CI (lint.yml): eslint -> biome ci
- Update VSCode config: biomejs.biome extension + default formatter
- Apply biome format --write to all files
- Update submodule pointers for react and elysia

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

package.json

@@ -2,12 +2,13 @@
   "name": "asepharyana-hub",
   "private": true,
   "scripts": {
-    "lint": "eslint .",
-    "format": "prettier --write .",
+    "lint": "biome lint .",
+    "format": "biome format --write .",
+    "check": "biome check --write .",
+    "ci": "biome ci .",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "devDependencies": {
-    "prettier": "^3.4.2",
-    "eslint": "^9.18.0"
+    "@biomejs/biome": "2.5.3"
   }
 }