Feat/provider icon color (#385)

* feat(ui): add color prop support to ProviderIcon component

* feat(health): add stream check core functionality

Add new stream-based health check module to replace model_test:
- Add stream_check command layer with single and batch provider checks
- Add stream_check DAO layer for config and log persistence
- Add stream_check service layer with retry mechanism and health status evaluation
- Add frontend HealthStatusIndicator component
- Add frontend useStreamCheck hook

This provides more comprehensive health checking capabilities.

* refactor(health): replace model_test with stream_check

Replace model_test module with stream_check across the codebase:
- Remove model_test command and service modules
- Update command registry in lib.rs to use stream_check commands
- Update module exports in commands/mod.rs and services/mod.rs
- Remove frontend useModelTest hook
- Update stream_check command implementation

This refactoring provides clearer naming and better separation of concerns.

* refactor(db): clean up unused database tables and optimize schema

Remove deprecated and unused database tables:
- Remove proxy_usage table (replaced by proxy_request_logs)
- Remove usage_daily_stats table (aggregation done on-the-fly)
- Rename model_test_logs to stream_check_logs with updated schema
- Remove related DAO methods for proxy_usage
- Update usage_stats service to use proxy_request_logs only
- Refactor usage_script to work with new schema

This simplifies the database schema and removes redundant data storage.

* refactor(ui): update frontend components for stream check

Update frontend components to use stream check API:
- Refactor ModelTestConfigPanel to use stream check config
- Update API layer to use stream_check commands
- Add HealthStatus type and StreamCheckResult interface
- Update ProviderList to use new health check integration
- Update AutoFailoverConfigPanel with stream check references
- Improve UI layout and configuration options

This completes the frontend migration from model_test to stream_check.

* feat(health): add configurable test models and reasoning effort support

Enhance stream check service with configurable test models:
- Add claude_model, codex_model, gemini_model to StreamCheckConfig
- Support reasoning effort syntax (model@level or model#level)
- Parse and apply reasoning_effort for OpenAI-compatible models
- Remove hardcoded model names from check functions
- Add unit tests for model parsing logic
- Remove obsolete model_test source files

This allows users to customize which models are used for health checks.

src/components/proxy/AutoFailoverConfigPanel.tsx

@@ -80,11 +80,11 @@ export function AutoFailoverConfigPanel({
 
   return (
     <div className="border-0 rounded-none shadow-none bg-transparent">
-      {/* Header Switch moved to parent accordion logic or kept here absolutely positioned if styling permits. 
-            Since we need it in the accordion header, and this component is inside the content, we can use a portal or 
-            absolute positioning trick similar to ProxyPanel, OR cleaner, just duplicate the switch logic in SettingsPage 
-            and pass it down. But for now, let's use the absolute positioning trick to "lift" it visually. 
-            Better yet, let's just render the content directly without the wrapping Card header/collapse logic 
+      {/* Header Switch moved to parent accordion logic or kept here absolutely positioned if styling permits.
+            Since we need it in the accordion header, and this component is inside the content, we can use a portal or
+            absolute positioning trick similar to ProxyPanel, OR cleaner, just duplicate the switch logic in SettingsPage
+            and pass it down. But for now, let's use the absolute positioning trick to "lift" it visually.
+            Better yet, let's just render the content directly without the wrapping Card header/collapse logic
             since the user requested "click to expand is detailed info, no need to fold again" (implying the accordion handles folding).
         */}