feat: standardize input styling with tier system, add depth and admin features

- Define 4 input tier CSS classes (input-standard, input-search, input-embedded, input-danger)
  in globals.css, migrating ~50 inputs across ~28 component files to use them
- Add subtle border and inset shadow to solid input tiers for resting-state visibility
- Fix focus ring clipping in settings panel scroll container
- Fix phantom Tailwind tokens (border-border-primary, placeholder-txt-muted)
- Add admin user management panel, storage management, and account deletion utilities

packages/web/tailwind.config.js

@@ -68,6 +68,7 @@ export default {
         'elevation-low': '0 1px 0 rgba(4, 4, 5, 0.2), 0 1.5px 0 rgba(6, 6, 7, 0.05), 0 2px 0 rgba(4, 4, 5, 0.05)',
         'elevation-high': '0 8px 16px rgba(0, 0, 0, 0.24)',
         'glass': '0 2px 8px rgba(0,0,0,0.25), 0 8px 24px rgba(0,0,0,0.15), inset 0 1px 0 var(--glass-highlight)',
+        'input': 'inset 0 1px 2px rgba(0, 0, 0, 0.25)',
       },
       fontFamily: {
         sans: ['DM Sans', '-apple-system', 'BlinkMacSystemFont', 'system-ui', 'sans-serif'],