refactor(migration): run dedupe only during first-time migration; remove startup dedupe

- Remove per-startup dedupe; keep it limited to migration
- Call dedupe at end of migrate_copies_into_config, then write marker
- Avoid unintended changes on every app launch

src-tauri/src/lib.rs

@@ -66,11 +66,6 @@ pub fn run() {
                 // 确保两个 App 条目存在
                 config_guard.ensure_app(&app_config::AppType::Claude);
                 config_guard.ensure_app(&app_config::AppType::Codex);
-                // 启动去重：名称(忽略大小写)+API Key
-                let removed = migration::dedupe_config(&mut *config_guard);
-                if removed > 0 {
-                    log::info!("已去重重复供应商 {} 个", removed);
-                }
             }
 
             // 保存配置

src-tauri/src/migration.rs

@@ -395,6 +395,12 @@ pub fn migrate_copies_into_config(config: &mut MultiAppConfig) -> Result<bool, S
     }
 
     // 标记完成
+    // 仅在迁移阶段执行一次全量去重（忽略大小写的名称 + API Key）
+    let removed = dedupe_config(config);
+    if removed > 0 {
+        log::info!("迁移阶段已去重重复供应商 {} 个", removed);
+    }
+
     fs::write(&marker, b"done").map_err(|e| format!("写入迁移标记失败: {}", e))?;
     Ok(true)
 }