feat: complete UI redesign with DaisyUI + Tailwind CSS v4

Design system overhaul using DaisyUI v5 on Tailwind CSS v4:

- Custom 'ohmstream' dark theme with orange primary (#FF9F1C),
  magenta secondary, gold accent matching existing palette
- Tailwind CSS-first config (input.css source, style.css built output)
- DaisyUI components: navbar, drawer, cards, badges, alerts, tables,
  progress bars, tabs, toggles, stats, form controls, tooltips
- Mobile-first responsive layout with drawer navigation
- Eliminated ~500+ lines of embedded CSS across 15+ template files
- Removed all inline style spam from admin_panel and settings_section
- Preserved all HTMX triggers, Alpine.js state, and Jinja2 logic
- Updated auth-ui.js for DaisyUI tab-active class compatibility

Build: npm run build:css (minified) / npm run watch:css (dev)

templates/components/login_prompt.html

@@ -1,4 +1,7 @@
-<div class="login-prompt" style="text-align: center; padding: 40px 20px;">
-    <i class="fa-solid fa-lock" style="font-size: 2rem; color: #FF9F1C; margin-bottom: 15px;"></i>
-    <p style="color: #8a8f98; font-size: 0.95rem;">Connectez-vous pour accéder à cette section.</p>
+<div class="flex flex-col items-center justify-center py-16 text-base-content/50">
+    <i class="fa-solid fa-lock text-4xl text-primary mb-4"></i>
+    <p class="text-base">Connectez-vous pour accéder à cette section.</p>
+    <a href="/login" class="btn btn-sm btn-primary mt-4 gap-2">
+        <i class="fa-solid fa-right-to-bracket"></i> Se connecter
+    </a>
 </div>