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)

static/css/input.css

@@ -0,0 +1,34 @@
+@import "tailwindcss";
+@plugin "daisyui";
+
+@plugin "daisyui/theme" {
+  name: "ohmstream";
+  default: true;
+  prefersdark: false;
+  color-scheme: dark;
+  --color-base-100: oklch(0.15 0.01 260);        /* #1a1c20 - main bg */
+  --color-base-200: oklch(0.18 0.01 260);        /* #202327 - card bg */
+  --color-base-300: oklch(0.22 0.01 260);        /* #2a2d32 - elevated */
+  --color-base-content: oklch(0.93 0.01 80);      /* #eae8e4 - text */
+  --color-primary: oklch(0.72 0.16 65);           /* #FF9F1C - orange */
+  --color-primary-content: oklch(0.18 0.02 65);   /* #1a1400 */
+  --color-secondary: oklch(0.65 0.12 310);        /* #e05faa - magenta */
+  --color-secondary-content: oklch(0.95 0 0);     
+  --color-accent: oklch(0.78 0.14 75);            /* #FFBF69 - gold */
+  --color-accent-content: oklch(0.18 0.02 75);    
+  --color-neutral: oklch(0.25 0.01 260);         /* #292b30 */
+  --color-neutral-content: oklch(0.9 0.01 80);    
+  --color-info: oklch(0.65 0.15 250);            /* #3b7ddd */
+  --color-success: oklch(0.65 0.14 155);          /* #2d936c */
+  --color-warning: oklch(0.75 0.16 75);           /* #f0a500 */
+  --color-error: oklch(0.6 0.2 25);               /* #e63946 */
+  --color-error-content: oklch(0.95 0 0);         
+  --radius-selector: 0.5rem;
+  --radius-field: 0.375rem;
+  --radius-box: 0.5rem;
+  --size-selector: 0.25rem;
+  --size-field: 0.25rem;
+  --border: 1px;
+  --depth: 1;
+  --noise: 0;
+}

static/js/auth-ui.js

@@ -104,19 +104,23 @@ function switchTab(tab) {
   const tabs = document.querySelectorAll('.auth-tab');
   const forms = document.querySelectorAll('.auth-form');
 
-  tabs.forEach(t => t.classList.remove('active'));
-  forms.forEach(f => f.classList.remove('active'));
+  // Remove active states — DaisyUI uses tab-active on tabs, hidden on forms
+  tabs.forEach(t => t.classList.remove('tab-active'));
+  forms.forEach(f => f.classList.add('hidden'));
 
   if (tab === 'login') {
-    tabs[0].classList.add('active');
-    document.getElementById('loginForm').classList.add('active');
+    tabs[0].classList.add('tab-active');
+    document.getElementById('loginForm').classList.remove('hidden');
   } else {
-    tabs[1].classList.add('active');
-    document.getElementById('registerForm').classList.add('active');
+    tabs[1].classList.add('tab-active');
+    document.getElementById('registerForm').classList.remove('hidden');
   }
 
-  document.getElementById('authError').classList.remove('show');
-  document.getElementById('authSuccess').classList.remove('show');
+  // Hide alerts on tab switch
+  const authError = document.getElementById('authError');
+  const authSuccess = document.getElementById('authSuccess');
+  if (authError) authError.classList.add('hidden');
+  if (authSuccess) authSuccess.classList.add('hidden');
 }
 
 window.authUi = {