Feat/auto failover (#367)

* feat(db): add circuit breaker config table and provider proxy target APIs

Add database support for auto-failover feature:

- Add circuit_breaker_config table for storing failover thresholds
- Add get/update_circuit_breaker_config methods in proxy DAO
- Add reset_provider_health method for manual recovery
- Add set_proxy_target and get_proxy_targets methods in providers DAO
  for managing multi-provider failover configuration

* feat(proxy): implement circuit breaker and provider router for auto-failover

Add core failover logic:

- CircuitBreaker: Tracks provider health with three states:
  - Closed: Normal operation, requests pass through
  - Open: Circuit broken after consecutive failures, skip provider
  - HalfOpen: Testing recovery with limited requests
- ProviderRouter: Routes requests across multiple providers with:
  - Health tracking and automatic failover
  - Configurable failure/success thresholds
  - Auto-disable proxy target after reaching failure threshold
  - Support for manual circuit breaker reset
- Export new types in proxy module

* feat(proxy): add failover Tauri commands and integrate with forwarder

Expose failover functionality to frontend:

- Add Tauri commands: get_proxy_targets, set_proxy_target,
  get_provider_health, reset_circuit_breaker,
  get/update_circuit_breaker_config, get_circuit_breaker_stats
- Register all new commands in lib.rs invoke handler
- Update forwarder with improved error handling and logging
- Integrate ProviderRouter with proxy server startup
- Add provider health tracking in request handlers

* feat(frontend): add failover API layer and TanStack Query hooks

Add frontend data layer for failover management:

- Add failover.ts API: Tauri invoke wrappers for all failover commands
- Add failover.ts query hooks: TanStack Query mutations and queries
  - useProxyTargets, useProviderHealth queries
  - useSetProxyTarget, useResetCircuitBreaker mutations
  - useCircuitBreakerConfig query and mutation
- Update queries.ts with provider health query key
- Update mutations.ts to invalidate health on provider changes
- Add CircuitBreakerConfig and ProviderHealth types

* feat(ui): add auto-failover configuration UI and provider health display

Add comprehensive UI for failover management:

Components:
- ProviderHealthBadge: Display provider health status with color coding
- CircuitBreakerConfigPanel: Configure failure/success thresholds,
  timeout duration, and error rate limits
- AutoFailoverConfigPanel: Manage proxy targets with drag-and-drop
  priority ordering and individual enable/disable controls
- ProxyPanel: Integrate failover tabs for unified proxy management

Provider enhancements:
- ProviderCard: Show health badge and proxy target indicator
- ProviderActions: Add "Set as Proxy Target" action
- EditProviderDialog: Add is_proxy_target toggle
- ProviderList: Support proxy target filtering mode

Other:
- Update App.tsx routing for settings integration
- Update useProviderActions hook with proxy target mutation
- Fix ProviderList tests for updated component API

* fix(usage): stabilize date range to prevent infinite re-renders

* feat(backend): add tool version check command

Add get_tool_versions command to check local and latest versions of
Claude, Codex, and Gemini CLI tools:

- Detect local installed versions via command line execution
- Fetch latest versions from npm registry (Claude, Gemini)
  and GitHub releases API (Codex)
- Return comprehensive version info including error details
  for uninstalled tools
- Register command in Tauri invoke handler

* style(ui): format accordion component code style

Apply consistent code formatting to accordion component:
- Convert double quotes to semicolons at line endings
- Adjust indentation to 2-space standard
- Align with project code style conventions

* refactor(providers): update provider card styling to use theme tokens

Replace hardcoded color classes with semantic design tokens:
- Use bg-card, border-border, text-card-foreground instead of glass-card
- Replace gray/white color literals with muted/foreground tokens
- Change proxy target indicator color from purple to green
- Improve hover states with border-border-active
- Ensure consistent dark mode support via CSS variables

* refactor(proxy): simplify auto-failover config panel structure

Restructure AutoFailoverConfigPanel for better integration:
- Remove internal Card wrapper and expansion toggle (now handled by parent)
- Extract enabled state to props for external control
- Simplify loading state display
- Clean up redundant CardHeader/CardContent wrappers
- ProxyPanel: reduce complexity by delegating to parent components

* feat(settings): enhance settings page with accordion layout and tool versions

Major settings page improvements:

AboutSection:
- Add local tool version detection (Claude, Codex, Gemini)
- Display installed vs latest version comparison with visual indicators
- Show update availability badges and environment check cards

SettingsPage:
- Reorganize advanced settings into collapsible accordion sections
- Add proxy control panel with inline status toggle
- Integrate auto-failover configuration with accordion UI
- Add database and cost calculation config sections

DirectorySettings & WindowSettings:
- Minor styling adjustments for consistency

settings.ts API:
- Add getToolVersions() wrapper for new backend command

* refactor(usage): restructure usage dashboard components

Comprehensive usage statistics panel refactoring:

UsageDashboard:
- Reorganize layout with improved section headers
- Add better loading states and empty state handling

ModelStatsTable & ProviderStatsTable:
- Minor styling updates for consistency

ModelTestConfigPanel & PricingConfigPanel:
- Simplify component structure
- Remove redundant Card wrappers
- Improve form field organization

RequestLogTable:
- Enhance table layout with better column sizing
- Improve pagination controls

UsageSummaryCards:
- Update card styling with semantic tokens
- Better responsive grid layout

UsageTrendChart:
- Refine chart container styling
- Improve legend and tooltip display

* chore(deps): add accordion and animation dependencies

Package updates:
- Add @radix-ui/react-accordion for collapsible sections
- Add cmdk for command palette support
- Add framer-motion for enhanced animations

Tailwind config:
- Add accordion-up/accordion-down animations
- Update darkMode config to support both selector and class
- Reorganize color and keyframe definitions for clarity

* style(app): update header and app switcher styling

App.tsx:
- Replace glass-header with explicit bg-background/80 backdrop-blur
- Update navigation button container to use bg-muted

AppSwitcher:
- Replace hardcoded gray colors with semantic muted/foreground tokens
- Ensure consistent dark mode support via CSS variables
- Add group class for better hover state transitions

package.json

@@ -50,6 +50,7 @@
     "@dnd-kit/utilities": "^3.2.2",
     "@hookform/resolvers": "^5.2.2",
     "@lobehub/icons-static-svg": "^1.73.0",
+    "@radix-ui/react-accordion": "^1.2.12",
     "@radix-ui/react-checkbox": "^1.3.3",
     "@radix-ui/react-dialog": "^1.1.15",
     "@radix-ui/react-dropdown-menu": "^2.1.16",
@@ -67,7 +68,9 @@
     "@tauri-apps/plugin-updater": "^2.0.0",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
+    "cmdk": "^1.1.1",
     "codemirror": "^6.0.2",
+    "framer-motion": "^12.23.25",
     "i18next": "^25.5.2",
     "jsonc-parser": "^3.2.1",
     "lucide-react": "^0.542.0",