feat(frontend): add API client, layout, and routing

- Create Axios-based API client with sources, jobs, and dashboard endpoints
- Add responsive Layout component with navigation sidebar
- Set up React Router with Dashboard, Backups, and Settings routes
- Configure TanStack Query provider with default options
- Use lucide-react for navigation icons

frontend/node_modules/loupe/lib/string.js

@@ -0,0 +1,29 @@
+import { truncate } from './helpers'
+
+const stringEscapeChars = new RegExp(
+  "['\\u0000-\\u001f\\u007f-\\u009f\\u00ad\\u0600-\\u0604\\u070f\\u17b4\\u17b5" +
+    '\\u200c-\\u200f\\u2028-\\u202f\\u2060-\\u206f\\ufeff\\ufff0-\\uffff]',
+  'g'
+)
+
+const escapeCharacters = {
+  '\b': '\\b',
+  '\t': '\\t',
+  '\n': '\\n',
+  '\f': '\\f',
+  '\r': '\\r',
+  "'": "\\'",
+  '\\': '\\\\',
+}
+const hex = 16
+const unicodeLength = 4
+function escape(char) {
+  return escapeCharacters[char] || `\\u${`0000${char.charCodeAt(0).toString(hex)}`.slice(-unicodeLength)}`
+}
+
+export default function inspectString(string, options) {
+  if (stringEscapeChars.test(string)) {
+    string = string.replace(stringEscapeChars, escape)
+  }
+  return options.stylize(`'${truncate(string, options.truncate - 2)}'`, 'string')
+}