A warmer, friendlier admin: first pass

- The INBUXA palette on warm surfaces, softer cards, buttons and inputs, and
  self-hosted Inter and Space Grotesk.
- Each section's icon sits on a colored tile, colored by what the section is
  about.
- The sidebar gets a guide line for sub-pages and a labeled Management /
  Settings / Account switch, and folds to a rail of tiles (remembered).
- Every page has a header with its section's tile.
- Fields and pages with no label of their own are spelled out in words
  (defaultCertificateId becomes Default certificate ID).
- The dashboard greets you, and its stat cards wear colored tiles.
- Unavailable live numbers are a calm note, not an error.
- The cat appears in empty lists and while loading.
- Chart colors work again: they were hex values wrapped in hsl().

src/main.tsx

@@ -9,6 +9,8 @@ import { StrictMode } from 'react';
 import { createRoot } from 'react-dom/client';
 import { createBrowserRouter, RouterProvider } from 'react-router-dom';
 import './i18n';
+import '@fontsource-variable/inter';
+import '@fontsource-variable/space-grotesk';
 import './index.css';
 import App from './App';
 import LoginPage from './pages/LoginPage';