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-tauri/src/database/dao/proxy.rs

@@ -210,83 +210,6 @@ impl Database {
         Ok(())
     }
 
-    // ==================== Proxy Usage (可选) ====================
-
-    /// 记录代理使用统计
-    #[allow(dead_code)]
-    pub async fn record_proxy_usage(&self, record: &ProxyUsageRecord) -> Result<(), AppError> {
-        let conn = lock_conn!(self.conn);
-
-        conn.execute(
-            "INSERT INTO proxy_usage 
-             (provider_id, app_type, endpoint, request_tokens, response_tokens,
-              status_code, latency_ms, error, timestamp)
-             VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9)",
-            rusqlite::params![
-                &record.provider_id,
-                &record.app_type,
-                &record.endpoint,
-                record.request_tokens,
-                record.response_tokens,
-                record.status_code as i64,
-                record.latency_ms as i64,
-                &record.error,
-                &record.timestamp,
-            ],
-        )
-        .map_err(|e| AppError::Database(e.to_string()))?;
-
-        Ok(())
-    }
-
-    /// 查询最近的使用统计
-    #[allow(dead_code)]
-    pub async fn get_recent_usage(
-        &self,
-        provider_id: &str,
-        app_type: &str,
-        limit: usize,
-    ) -> Result<Vec<ProxyUsageRecord>, AppError> {
-        let conn = lock_conn!(self.conn);
-
-        let mut stmt = conn
-            .prepare(
-                "SELECT provider_id, app_type, endpoint, request_tokens, response_tokens,
-                        status_code, latency_ms, error, timestamp
-                 FROM proxy_usage
-                 WHERE provider_id = ?1 AND app_type = ?2
-                 ORDER BY timestamp DESC
-                 LIMIT ?3",
-            )
-            .map_err(|e| AppError::Database(e.to_string()))?;
-
-        let rows = stmt
-            .query_map(
-                rusqlite::params![provider_id, app_type, limit as i64],
-                |row| {
-                    Ok(ProxyUsageRecord {
-                        provider_id: row.get(0)?,
-                        app_type: row.get(1)?,
-                        endpoint: row.get(2)?,
-                        request_tokens: row.get(3)?,
-                        response_tokens: row.get(4)?,
-                        status_code: row.get::<_, i64>(5)? as u16,
-                        latency_ms: row.get::<_, i64>(6)? as u64,
-                        error: row.get(7)?,
-                        timestamp: row.get(8)?,
-                    })
-                },
-            )
-            .map_err(|e| AppError::Database(e.to_string()))?;
-
-        let mut records = Vec::new();
-        for row in rows {
-            records.push(row.map_err(|e| AppError::Database(e.to_string()))?);
-        }
-
-        Ok(records)
-    }
-
     // ==================== Circuit Breaker Config ====================
 
     /// 获取熔断器配置