Feature/glassmorphism unified UI (#508)

* feat(frontend): unified glassmorphism UI rework with bug fixes

- Create _glass-system.scss unified design system (~450 lines)
  - CSS custom properties for glass tokens (bg, blur, shadow, border)
  - Theme-aware variables (dark/light) eliminating manual overrides
  - Glass surface mixins (subtle/medium/strong variants)
  - Component classes, button system, form elements, utilities

- Fix notification bell click-outside bug
  - Replace broken querySelector with Vue template refs
  - Add @click.stop modifier and onUnmounted cleanup
  - Make bell visible on all screen sizes (was hidden on mobile)

- Fix login state refresh bug
  - LoginView now uses useAuth().login() composable
  - Replace window.location.href with router.push('/')
  - Auth state updates reactively via module-level singleton refs

- Remove duplicate hamburger menu navigation
  - Delete mobile menu overlay, hamburger button, related functions
  - SidebarNav for desktop, BottomNav for mobile (clean separation)

- Migrate 13 components to glass system variables
  - Replace hardcoded rgba/blur/shadow with glass tokens
  - Remove [data-theme] overrides (glass vars are theme-aware)
  - Add @supports fallbacks for backdrop-filter

- Remove old _glass.scss import from main.scss (dead code)

* feat: add .gitignore to exclude cache and project.local.yml

* feat: update .gitignore to include .pytest_cache and .serena

* feat(frontend): expand streamer settings, clean up settings UI

- Add codec preferences, max concurrent recordings, and global cleanup
  policy toggle to streamer settings modal (StreamerDetailView)
- Update backend API to handle new per-streamer settings fields
  (maxStreams, supportedCodecs, useGlobalCleanupPolicy)
- Fix saveSettings to call working PUT endpoint directly instead of
  broken composable endpoint
- Hide connection-status block when not connected (TwitchConnectionPanel)
- Remove borders from steps-container and benefits-section
- Hide duplicate section headers on mobile settings pages
- Various glassmorphism UI polish: video controls, chapter seeking,
  notification panel, force-record visibility, responsive video wrapper,
  dashboard title cutoff, error overlay mobile fix

* Remove outdated ADRs and architecture review documents; implement circuit breaker for Twitch API and Prometheus metrics for observability; enhance security by addressing critical vulnerabilities in authentication and session management; improve error handling and logging practices; and refine overall application architecture for better reliability and performance.

* fix: update copyright year in LICENSE file to 2026

* feat: add frontend development guide with quick start, dev scripts, and mock mode instructions

* fix(lint): apply ruff formatting to streamers.py and metadata_service.py

Author: Serph91P

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2025 StreamVault Contributors
+Copyright (c) 2026 StreamVault Contributors
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

app/frontend/DEVELOPMENT.md

@@ -5,6 +5,8 @@
   "type": "module",
   "scripts": {
     "dev": "vite",
+    "dev:mock": "VITE_USE_MOCK_DATA=true vite",
+    "dev:live": "VITE_USE_MOCK_DATA=false vite",
     "build": "run-p type-check \"build-only {@}\" --",
     "preview": "vite preview",
     "build-only": "vite build",