refactor: standardize code formatting and linting configuration

- Replace .eslintrc.js with .eslintrc.cjs for better ES module compatibility
- Add .prettierrc configuration for consistent code formatting
- Update package.json with new lint and format scripts
- Add nodemon.json for development hot reloading configuration
- Standardize code formatting across all JavaScript and Vue files
- Update web admin SPA with improved linting rules and formatting
- Add prettier configuration to web admin SPA

🤖 Generated with [Claude Code](https://claude.ai/code)

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

.prettierrc

@@ -0,0 +1,14 @@
+{
+  "semi": false,
+  "trailingComma": "none",
+  "singleQuote": true,
+  "printWidth": 100,
+  "tabWidth": 2,
+  "useTabs": false,
+  "bracketSpacing": true,
+  "arrowParens": "always",
+  "endOfLine": "lf",
+  "quoteProps": "as-needed",
+  "bracketSameLine": false,
+  "proseWrap": "preserve"
+}