Feat/auto failover switch (#440)

* feat(failover): add auto-failover master switch with proxy integration

- Add persistent auto_failover_enabled setting in database
- Add get/set_auto_failover_enabled commands
- Provider router respects master switch state
- Proxy shutdown automatically disables failover
- Enabling failover auto-starts proxy server
- Optimistic updates for failover queue toggle

* feat(proxy): persist proxy takeover state across app restarts

- Add proxy_takeover_{app_type} settings for per-app state tracking
- Restore proxy takeover state automatically on app startup
- Preserve state on normal exit, clear on manual stop
- Add stop_with_restore_keep_state method for graceful shutdown

* fix(proxy): set takeover state for all apps in start_with_takeover

* fix(windows): hide console window when checking CLI versions

Add CREATE_NO_WINDOW flag to prevent command prompt from flashing
when detecting claude/codex/gemini CLI versions on Windows.

* refactor(failover): make auto-failover toggle per-app independent

- Change setting key from 'auto_failover_enabled' to 'auto_failover_enabled_{app_type}'
- Update provider_router to check per-app failover setting
- When failover disabled, use current provider only; when enabled, use queue order
- Add unit tests for failover enabled/disabled behavior

* feat(failover): auto-switch to higher priority provider on recovery

- After circuit breaker reset, check if recovered provider has higher priority
- Automatically switch back if queue_order is lower (higher priority)
- Stream health check now resets circuit breaker on success/degraded

* chore: remove unused start_proxy_with_takeover command

- Remove command registration from lib.rs
- Add comment clarifying failover queue is preserved on proxy stop

* feat(ui): integrate failover controls into provider cards

- Add failover toggle button to provider card actions
- Show priority badge (P1, P2, ...) for queued providers
- Highlight active provider with green border in failover mode
- Sync drag-drop order with failover queue
- Move per-app failover toggle to FailoverQueueManager
- Simplify SettingsPage failover section

* test(providers): add mocks for failover hooks in ProviderList tests

* refactor(failover): merge failover_queue table into providers

- Add in_failover_queue field to providers table
- Remove standalone failover_queue table and related indexes
- Simplify queue ordering by reusing sort_index field
- Remove reorder_failover_queue and set_failover_item_enabled commands
- Update frontend to use simplified FailoverQueueItem type

* fix(database): ensure in_failover_queue column exists for v2 databases

Add column check in create_tables to handle existing v2 databases
that were created before the failover queue refactor.

* fix(ui): differentiate active provider border color by proxy mode

- Use green border/gradient when proxy takeover is active
- Use blue border/gradient in normal mode (no proxy)
- Improves visual distinction between proxy and non-proxy states

* fix(database): clear provider health record when removing from failover queue

When a provider is removed from the failover queue, its health monitoring
is no longer needed. This change ensures the health record is also deleted
from the database to prevent stale data.

* fix(failover): improve cache cleanup for provider health and circuit breaker

- Use removeQueries instead of invalidateQueries when stopping proxy to
  completely clear health and circuit breaker caches
- Clear provider health and circuit breaker caches when removing from
  failover queue
- Refresh failover queue after drag-sort since queue order depends on
  sort_index
- Only show health badge when provider is in failover queue

* style: apply prettier formatting to App.tsx and ProviderList.tsx

* fix(proxy): handle missing health records and clear health on proxy stop

- Return default healthy state when provider health record not found
- Add clear_provider_health_for_app to clear health for specific app
- Clear app health records when stopping proxy takeover

* fix(proxy): track actual provider used in forwarding for accurate logging

Introduce ForwardResult and ForwardError structs to return the actual
provider that handled the request. This ensures usage statistics and
error logs reflect the correct provider after failover.

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

@@ -1,36 +1,32 @@
 //! 故障转移队列 DAO
 //!
-//! 管理代理模式下的故障转移队列
+//! 管理代理模式下的故障转移队列（基于 providers 表的 in_failover_queue 字段）
 
 use crate::database::{lock_conn, Database};
 use crate::error::AppError;
 use crate::provider::Provider;
 use serde::{Deserialize, Serialize};
-use std::time::{SystemTime, UNIX_EPOCH};
 
-/// 故障转移队列条目
+/// 故障转移队列条目（简化版，用于前端展示）
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct FailoverQueueItem {
     pub provider_id: String,
     pub provider_name: String,
-    pub queue_order: i32,
-    pub enabled: bool,
-    pub created_at: i64,
+    pub sort_index: Option<usize>,
 }
 
 impl Database {
-    /// 获取故障转移队列（按 queue_order 排序）
+    /// 获取故障转移队列（按 sort_index 排序）
     pub fn get_failover_queue(&self, app_type: &str) -> Result<Vec<FailoverQueueItem>, AppError> {
         let conn = lock_conn!(self.conn);
 
         let mut stmt = conn
             .prepare(
-                "SELECT fq.provider_id, p.name, fq.queue_order, fq.enabled, fq.created_at
-                 FROM failover_queue fq
-                 JOIN providers p ON fq.provider_id = p.id AND fq.app_type = p.app_type
-                 WHERE fq.app_type = ?1
-                 ORDER BY fq.queue_order ASC",
+                "SELECT id, name, sort_index
+                 FROM providers
+                 WHERE app_type = ?1 AND in_failover_queue = 1
+                 ORDER BY COALESCE(sort_index, 999999), id ASC",
             )
             .map_err(|e| AppError::Database(e.to_string()))?;
 
@@ -39,9 +35,7 @@ impl Database {
                 Ok(FailoverQueueItem {
                     provider_id: row.get(0)?,
                     provider_name: row.get(1)?,
-                    queue_order: row.get(2)?,
-                    enabled: row.get(3)?,
-                    created_at: row.get(4)?,
+                    sort_index: row.get(2)?,
                 })
             })
             .map_err(|e| AppError::Database(e.to_string()))?
@@ -53,43 +47,23 @@ impl Database {
 
     /// 获取故障转移队列中的供应商（完整 Provider 信息，按顺序）
     pub fn get_failover_providers(&self, app_type: &str) -> Result<Vec<Provider>, AppError> {
-        let queue = self.get_failover_queue(app_type)?;
         let all_providers = self.get_all_providers(app_type)?;
 
-        let mut result = Vec::new();
-        for item in queue {
-            if item.enabled {
-                if let Some(provider) = all_providers.get(&item.provider_id) {
-                    result.push(provider.clone());
-                }
-            }
-        }
+        let result: Vec<Provider> = all_providers
+            .into_values()
+            .filter(|p| p.in_failover_queue)
+            .collect();
 
         Ok(result)
     }
 
-    /// 添加供应商到故障转移队列末尾
+    /// 添加供应商到故障转移队列
     pub fn add_to_failover_queue(&self, app_type: &str, provider_id: &str) -> Result<(), AppError> {
         let conn = lock_conn!(self.conn);
 
-        // 获取当前最大 queue_order
-        let max_order: i32 = conn
-            .query_row(
-                "SELECT COALESCE(MAX(queue_order), 0) FROM failover_queue WHERE app_type = ?1",
-                [app_type],
-                |row| row.get(0),
-            )
-            .map_err(|e| AppError::Database(e.to_string()))?;
-
-        let now = SystemTime::now()
-            .duration_since(UNIX_EPOCH)
-            .unwrap_or_default()
-            .as_secs() as i64;
-
         conn.execute(
-            "INSERT OR IGNORE INTO failover_queue (app_type, provider_id, queue_order, enabled, created_at)
-             VALUES (?1, ?2, ?3, 1, ?4)",
-            rusqlite::params![app_type, provider_id, max_order + 1, now],
+            "UPDATE providers SET in_failover_queue = 1 WHERE id = ?1 AND app_type = ?2",
+            rusqlite::params![provider_id, app_type],
         )
         .map_err(|e| AppError::Database(e.to_string()))?;
 
@@ -104,103 +78,21 @@ impl Database {
     ) -> Result<(), AppError> {
         let conn = lock_conn!(self.conn);
 
-        // 获取被删除项的 queue_order
-        let removed_order: Option<i32> = conn
-            .query_row(
-                "SELECT queue_order FROM failover_queue WHERE app_type = ?1 AND provider_id = ?2",
-                [app_type, provider_id],
-                |row| row.get(0),
-            )
-            .ok();
-
-        // 删除该项
+        // 1. 从队列中移除
         conn.execute(
-            "DELETE FROM failover_queue WHERE app_type = ?1 AND provider_id = ?2",
-            [app_type, provider_id],
+            "UPDATE providers SET in_failover_queue = 0 WHERE id = ?1 AND app_type = ?2",
+            rusqlite::params![provider_id, app_type],
         )
         .map_err(|e| AppError::Database(e.to_string()))?;
 
-        // 重新排序后面的项（填补空隙）
-        if let Some(order) = removed_order {
-            conn.execute(
-                "UPDATE failover_queue
-                 SET queue_order = queue_order - 1
-                 WHERE app_type = ?1 AND queue_order > ?2",
-                rusqlite::params![app_type, order],
-            )
-            .map_err(|e| AppError::Database(e.to_string()))?;
-        }
+        // 2. 清除该供应商的健康状态（退出队列后不再需要健康监控）
+        conn.execute(
+            "DELETE FROM provider_health WHERE provider_id = ?1 AND app_type = ?2",
+            rusqlite::params![provider_id, app_type],
+        )
+        .map_err(|e| AppError::Database(e.to_string()))?;
 
-        Ok(())
-    }
-
-    /// 重新排序故障转移队列
-    /// provider_ids: 按新顺序排列的 provider_id 列表
-    pub fn reorder_failover_queue(
-        &self,
-        app_type: &str,
-        provider_ids: &[String],
-    ) -> Result<(), AppError> {
-        let conn = lock_conn!(self.conn);
-
-        // 使用事务确保原子性
-        conn.execute("BEGIN TRANSACTION", [])
-            .map_err(|e| AppError::Database(e.to_string()))?;
-
-        let result = (|| {
-            for (index, provider_id) in provider_ids.iter().enumerate() {
-                conn.execute(
-                    "UPDATE failover_queue
-                     SET queue_order = ?3
-                     WHERE app_type = ?1 AND provider_id = ?2",
-                    rusqlite::params![app_type, provider_id, (index + 1) as i32],
-                )
-                .map_err(|e| AppError::Database(e.to_string()))?;
-            }
-            Ok(())
-        })();
-
-        match result {
-            Ok(_) => {
-                conn.execute("COMMIT", [])
-                    .map_err(|e| AppError::Database(e.to_string()))?;
-                Ok(())
-            }
-            Err(e) => {
-                conn.execute("ROLLBACK", []).ok();
-                Err(e)
-            }
-        }
-    }
-
-    /// 设置故障转移队列中供应商的启用状态
-    pub fn set_failover_item_enabled(
-        &self,
-        app_type: &str,
-        provider_id: &str,
-        enabled: bool,
-    ) -> Result<(), AppError> {
-        let conn = lock_conn!(self.conn);
-
-        let rows_affected = conn
-            .execute(
-                "UPDATE failover_queue SET enabled = ?3 WHERE app_type = ?1 AND provider_id = ?2",
-                rusqlite::params![app_type, provider_id, enabled],
-            )
-            .map_err(|e| AppError::Database(e.to_string()))?;
-
-        if rows_affected == 0 {
-            log::warn!(
-                "set_failover_item_enabled: 未找到匹配记录 app_type={app_type}, provider_id={provider_id}"
-            );
-            return Err(AppError::Database(format!(
-                "未找到故障转移队列项: app_type={app_type}, provider_id={provider_id}"
-            )));
-        }
-
-        log::info!(
-            "set_failover_item_enabled: 已更新 app_type={app_type}, provider_id={provider_id}, enabled={enabled}"
-        );
+        log::info!("已从故障转移队列移除供应商 {provider_id} ({app_type}), 并清除其健康状态");
 
         Ok(())
     }
@@ -209,8 +101,11 @@ impl Database {
     pub fn clear_failover_queue(&self, app_type: &str) -> Result<(), AppError> {
         let conn = lock_conn!(self.conn);
 
-        conn.execute("DELETE FROM failover_queue WHERE app_type = ?1", [app_type])
-            .map_err(|e| AppError::Database(e.to_string()))?;
+        conn.execute(
+            "UPDATE providers SET in_failover_queue = 0 WHERE app_type = ?1",
+            [app_type],
+        )
+        .map_err(|e| AppError::Database(e.to_string()))?;
 
         Ok(())
     }
@@ -223,15 +118,15 @@ impl Database {
     ) -> Result<bool, AppError> {
         let conn = lock_conn!(self.conn);
 
-        let count: i32 = conn
+        let in_queue: bool = conn
             .query_row(
-                "SELECT COUNT(*) FROM failover_queue WHERE app_type = ?1 AND provider_id = ?2",
-                [app_type, provider_id],
+                "SELECT in_failover_queue FROM providers WHERE id = ?1 AND app_type = ?2",
+                rusqlite::params![provider_id, app_type],
                 |row| row.get(0),
             )
-            .map_err(|e| AppError::Database(e.to_string()))?;
+            .unwrap_or(false);
 
-        Ok(count > 0)
+        Ok(in_queue)
     }
 
     /// 获取可添加到故障转移队列的供应商（不在队列中的）
@@ -240,14 +135,10 @@ impl Database {
         app_type: &str,
     ) -> Result<Vec<Provider>, AppError> {
         let all_providers = self.get_all_providers(app_type)?;
-        let queue = self.get_failover_queue(app_type)?;
-
-        let queue_ids: std::collections::HashSet<_> =
-            queue.iter().map(|item| &item.provider_id).collect();
 
         let available: Vec<Provider> = all_providers
             .into_values()
-            .filter(|p| !queue_ids.contains(&p.id))
+            .filter(|p| !p.in_failover_queue)
             .collect();
 
         Ok(available)

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

@@ -17,7 +17,7 @@ impl Database {
     ) -> Result<IndexMap<String, Provider>, AppError> {
         let conn = lock_conn!(self.conn);
         let mut stmt = conn.prepare(
-            "SELECT id, name, settings_config, website_url, category, created_at, sort_index, notes, icon, icon_color, meta
+            "SELECT id, name, settings_config, website_url, category, created_at, sort_index, notes, icon, icon_color, meta, in_failover_queue
              FROM providers WHERE app_type = ?1
              ORDER BY COALESCE(sort_index, 999999), created_at ASC, id ASC"
         ).map_err(|e| AppError::Database(e.to_string()))?;
@@ -35,6 +35,7 @@ impl Database {
                 let icon: Option<String> = row.get(8)?;
                 let icon_color: Option<String> = row.get(9)?;
                 let meta_str: String = row.get(10)?;
+                let in_failover_queue: bool = row.get(11)?;
 
                 let settings_config =
                     serde_json::from_str(&settings_config_str).unwrap_or(serde_json::Value::Null);
@@ -54,6 +55,7 @@ impl Database {
                         meta: Some(meta),
                         icon,
                         icon_color,
+                        in_failover_queue,
                     },
                 ))
             })
@@ -129,7 +131,7 @@ impl Database {
     ) -> Result<Option<Provider>, AppError> {
         let conn = lock_conn!(self.conn);
         let result = conn.query_row(
-            "SELECT name, settings_config, website_url, category, created_at, sort_index, notes, icon, icon_color, meta
+            "SELECT name, settings_config, website_url, category, created_at, sort_index, notes, icon, icon_color, meta, in_failover_queue
              FROM providers WHERE id = ?1 AND app_type = ?2",
             params![id, app_type],
             |row| {
@@ -143,6 +145,7 @@ impl Database {
                 let icon: Option<String> = row.get(7)?;
                 let icon_color: Option<String> = row.get(8)?;
                 let meta_str: String = row.get(9)?;
+                let in_failover_queue: bool = row.get(10)?;
 
                 let settings_config = serde_json::from_str(&settings_config_str).unwrap_or(serde_json::Value::Null);
                 let meta: ProviderMeta = serde_json::from_str(&meta_str).unwrap_or_default();
@@ -159,6 +162,7 @@ impl Database {
                     meta: Some(meta),
                     icon,
                     icon_color,
+                    in_failover_queue,
                 })
             },
         );
@@ -184,17 +188,18 @@ impl Database {
         let mut meta_clone = provider.meta.clone().unwrap_or_default();
         let endpoints = std::mem::take(&mut meta_clone.custom_endpoints);
 
-        // 检查是否存在（用于判断新增/更新，以及保留 is_current）
-        let existing: Option<bool> = tx
+        // 检查是否存在（用于判断新增/更新，以及保留 is_current 和 in_failover_queue）
+        let existing: Option<(bool, bool)> = tx
             .query_row(
-                "SELECT is_current FROM providers WHERE id = ?1 AND app_type = ?2",
+                "SELECT is_current, in_failover_queue FROM providers WHERE id = ?1 AND app_type = ?2",
                 params![provider.id, app_type],
-                |row| row.get(0),
+                |row| Ok((row.get(0)?, row.get(1)?)),
             )
             .ok();
 
         let is_update = existing.is_some();
-        let is_current = existing.unwrap_or(false);
+        let (is_current, in_failover_queue) =
+            existing.unwrap_or((false, provider.in_failover_queue));
 
         if is_update {
             // 更新模式：使用 UPDATE 避免触发 ON DELETE CASCADE
@@ -210,8 +215,9 @@ impl Database {
                     icon = ?8,
                     icon_color = ?9,
                     meta = ?10,
-                    is_current = ?11
-                WHERE id = ?12 AND app_type = ?13",
+                    is_current = ?11,
+                    in_failover_queue = ?12
+                WHERE id = ?13 AND app_type = ?14",
                 params![
                     provider.name,
                     serde_json::to_string(&provider.settings_config).unwrap(),
@@ -224,6 +230,7 @@ impl Database {
                     provider.icon_color,
                     serde_json::to_string(&meta_clone).unwrap(),
                     is_current,
+                    in_failover_queue,
                     provider.id,
                     app_type,
                 ],
@@ -234,8 +241,8 @@ impl Database {
             tx.execute(
                 "INSERT INTO providers (
                     id, app_type, name, settings_config, website_url, category,
-                    created_at, sort_index, notes, icon, icon_color, meta, is_current
-                ) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12, ?13)",
+                    created_at, sort_index, notes, icon, icon_color, meta, is_current, in_failover_queue
+                ) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12, ?13, ?14)",
                 params![
                     provider.id,
                     app_type,
@@ -250,6 +257,7 @@ impl Database {
                     provider.icon_color,
                     serde_json::to_string(&meta_clone).unwrap(),
                     is_current,
+                    in_failover_queue,
                 ],
             )
             .map_err(|e| AppError::Database(e.to_string()))?;

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

@@ -102,28 +102,45 @@ impl Database {
         provider_id: &str,
         app_type: &str,
     ) -> Result<ProviderHealth, AppError> {
-        let conn = lock_conn!(self.conn);
+        let result = {
+            let conn = lock_conn!(self.conn);
 
-        conn.query_row(
-            "SELECT provider_id, app_type, is_healthy, consecutive_failures,
-                    last_success_at, last_failure_at, last_error, updated_at
-             FROM provider_health
-             WHERE provider_id = ?1 AND app_type = ?2",
-            rusqlite::params![provider_id, app_type],
-            |row| {
-                Ok(ProviderHealth {
-                    provider_id: row.get(0)?,
-                    app_type: row.get(1)?,
-                    is_healthy: row.get::<_, i64>(2)? != 0,
-                    consecutive_failures: row.get::<_, i64>(3)? as u32,
-                    last_success_at: row.get(4)?,
-                    last_failure_at: row.get(5)?,
-                    last_error: row.get(6)?,
-                    updated_at: row.get(7)?,
-                })
-            },
-        )
-        .map_err(|e| AppError::Database(e.to_string()))
+            conn.query_row(
+                "SELECT provider_id, app_type, is_healthy, consecutive_failures,
+                        last_success_at, last_failure_at, last_error, updated_at
+                 FROM provider_health
+                 WHERE provider_id = ?1 AND app_type = ?2",
+                rusqlite::params![provider_id, app_type],
+                |row| {
+                    Ok(ProviderHealth {
+                        provider_id: row.get(0)?,
+                        app_type: row.get(1)?,
+                        is_healthy: row.get::<_, i64>(2)? != 0,
+                        consecutive_failures: row.get::<_, i64>(3)? as u32,
+                        last_success_at: row.get(4)?,
+                        last_failure_at: row.get(5)?,
+                        last_error: row.get(6)?,
+                        updated_at: row.get(7)?,
+                    })
+                },
+            )
+        };
+
+        match result {
+            Ok(health) => Ok(health),
+            // 缺少记录时视为健康（关闭后清空状态，再次打开时默认正常）
+            Err(rusqlite::Error::QueryReturnedNoRows) => Ok(ProviderHealth {
+                provider_id: provider_id.to_string(),
+                app_type: app_type.to_string(),
+                is_healthy: true,
+                consecutive_failures: 0,
+                last_success_at: None,
+                last_failure_at: None,
+                last_error: None,
+                updated_at: chrono::Utc::now().to_rfc3339(),
+            }),
+            Err(e) => Err(AppError::Database(e.to_string())),
+        }
     }
 
     /// 更新Provider健康状态
@@ -228,6 +245,20 @@ impl Database {
         Ok(())
     }
 
+    /// 清空指定应用的健康状态（关闭单个代理时使用）
+    pub async fn clear_provider_health_for_app(&self, app_type: &str) -> Result<(), AppError> {
+        let conn = lock_conn!(self.conn);
+
+        conn.execute(
+            "DELETE FROM provider_health WHERE app_type = ?1",
+            [app_type],
+        )
+        .map_err(|e| AppError::Database(e.to_string()))?;
+
+        log::debug!("Cleared provider health records for app {app_type}");
+        Ok(())
+    }
+
     /// 清空所有Provider健康状态（代理停止时调用）
     pub async fn clear_all_provider_health(&self) -> Result<(), AppError> {
         let conn = lock_conn!(self.conn);

src-tauri/src/database/schema.rs

@@ -31,6 +31,7 @@ impl Database {
                 icon_color TEXT,
                 meta TEXT NOT NULL DEFAULT '{}',
                 is_current BOOLEAN NOT NULL DEFAULT 0,
+                in_failover_queue BOOLEAN NOT NULL DEFAULT 0,
                 PRIMARY KEY (id, app_type)
             )",
             [],
@@ -312,29 +313,24 @@ impl Database {
             [],
         );
 
-        // 14. Failover Queue 表 (故障转移队列)
-        conn.execute(
-            "CREATE TABLE IF NOT EXISTS failover_queue (
-                id INTEGER PRIMARY KEY AUTOINCREMENT,
-                app_type TEXT NOT NULL,
-                provider_id TEXT NOT NULL,
-                queue_order INTEGER NOT NULL,
-                enabled INTEGER NOT NULL DEFAULT 1,
-                created_at INTEGER NOT NULL,
-                UNIQUE (app_type, provider_id),
-                FOREIGN KEY (provider_id, app_type) REFERENCES providers(id, app_type) ON DELETE CASCADE
-            )",
-            [],
-        )
-        .map_err(|e| AppError::Database(e.to_string()))?;
+        // 确保 in_failover_queue 列存在（对于已存在的 v2 数据库）
+        Self::add_column_if_missing(
+            conn,
+            "providers",
+            "in_failover_queue",
+            "BOOLEAN NOT NULL DEFAULT 0",
+        )?;
 
-        // 为故障转移队列创建索引
-        conn.execute(
-            "CREATE INDEX IF NOT EXISTS idx_failover_queue_order
-             ON failover_queue(app_type, queue_order)",
+        // 删除旧的 failover_queue 表（如果存在）
+        let _ = conn.execute("DROP INDEX IF EXISTS idx_failover_queue_order", []);
+        let _ = conn.execute("DROP TABLE IF EXISTS failover_queue", []);
+
+        // 为故障转移队列创建索引（基于 providers 表）
+        let _ = conn.execute(
+            "CREATE INDEX IF NOT EXISTS idx_providers_failover
+             ON providers(app_type, in_failover_queue, sort_index)",
             [],
-        )
-        .map_err(|e| AppError::Database(e.to_string()))?;
+        );
 
         Ok(())
     }
@@ -472,6 +468,26 @@ impl Database {
         Self::add_column_if_missing(conn, "providers", "limit_daily_usd", "TEXT")?;
         Self::add_column_if_missing(conn, "providers", "limit_monthly_usd", "TEXT")?;
         Self::add_column_if_missing(conn, "providers", "provider_type", "TEXT")?;
+        Self::add_column_if_missing(
+            conn,
+            "providers",
+            "in_failover_queue",
+            "BOOLEAN NOT NULL DEFAULT 0",
+        )?;
+
+        // 删除旧的 failover_queue 表（如果存在）
+        conn.execute("DROP INDEX IF EXISTS idx_failover_queue_order", [])
+            .map_err(|e| AppError::Database(format!("删除 failover_queue 索引失败: {e}")))?;
+        conn.execute("DROP TABLE IF EXISTS failover_queue", [])
+            .map_err(|e| AppError::Database(format!("删除 failover_queue 表失败: {e}")))?;
+
+        // 创建 failover 索引
+        conn.execute(
+            "CREATE INDEX IF NOT EXISTS idx_providers_failover
+             ON providers(app_type, in_failover_queue, sort_index)",
+            [],
+        )
+        .map_err(|e| AppError::Database(format!("创建 failover 索引失败: {e}")))?;
 
         // proxy_request_logs 表（包含所有字段）
         conn.execute(

src-tauri/src/database/tests.rs

@@ -245,6 +245,7 @@ fn dry_run_validates_schema_compatibility() {
             meta: None,
             icon: None,
             icon_color: None,
+            in_failover_queue: false,
         },
     );