fix(prompt): correct live file backfill priority in enable flow (#225)

Fix backfill logic in prompt enable workflow:
- Prioritize backfilling live file content to currently enabled prompt (prevent data loss)
- Create backup only when no enabled prompt exists and content is new (avoid duplicate backups)
- Implement staged persistence (save after backfill + save after enable)
- Add explicit logging for backfill/backup operations

Also simplify string formatting in prompt_files.rs with inline format strings.

src-tauri/src/prompt_files.rs

@@ -34,11 +34,8 @@ fn get_base_dir_with_fallback(
         .ok_or_else(|| {
             AppError::localized(
                 "home_dir_not_found",
-                format!("无法确定 {} 配置目录：用户主目录不存在", fallback_dir),
-                format!(
-                    "Cannot determine {} config directory: user home not found",
-                    fallback_dir
-                ),
+                format!("无法确定 {fallback_dir} 配置目录：用户主目录不存在"),
+                format!("Cannot determine {fallback_dir} config directory: user home not found"),
             )
         })
 }

src-tauri/src/services/prompt.rs

@@ -72,27 +72,38 @@ impl PromptService {
     }
 
     pub fn enable_prompt(state: &AppState, app: AppType, id: &str) -> Result<(), AppError> {
-        // 先保存当前文件内容（如果存在且没有对应的提示词）
+        // 回填当前 live 文件内容到已启用的提示词，或创建备份
         let target_path = prompt_file_path(&app)?;
         if target_path.exists() {
-            let mut cfg = state.config.write()?;
-            let prompts = match app {
-                AppType::Claude => &mut cfg.prompts.claude.prompts,
-                AppType::Codex => &mut cfg.prompts.codex.prompts,
-                AppType::Gemini => &mut cfg.prompts.gemini.prompts,
-            };
-
-            // 检查是否有已启用的提示词
-            let has_enabled = prompts.values().any(|p| p.enabled);
-
-            // 如果没有已启用的提示词，自动保存当前文件
-            if !has_enabled {
-                if let Ok(content) = std::fs::read_to_string(&target_path) {
-                    if !content.trim().is_empty() {
-                        // 检查是否已存在相同内容的提示词，避免重复备份
-                        let content_exists =
-                            prompts.values().any(|p| p.content.trim() == content.trim());
+            if let Ok(live_content) = std::fs::read_to_string(&target_path) {
+                if !live_content.trim().is_empty() {
+                    let mut cfg = state.config.write()?;
+                    let prompts = match app {
+                        AppType::Claude => &mut cfg.prompts.claude.prompts,
+                        AppType::Codex => &mut cfg.prompts.codex.prompts,
+                        AppType::Gemini => &mut cfg.prompts.gemini.prompts,
+                    };
 
+                    // 尝试回填到当前已启用的提示词
+                    if let Some((enabled_id, enabled_prompt)) = prompts
+                        .iter_mut()
+                        .find(|(_, p)| p.enabled)
+                        .map(|(id, p)| (id.clone(), p))
+                    {
+                        let timestamp = std::time::SystemTime::now()
+                            .duration_since(std::time::UNIX_EPOCH)
+                            .unwrap()
+                            .as_secs() as i64;
+                        enabled_prompt.content = live_content.clone();
+                        enabled_prompt.updated_at = Some(timestamp);
+                        log::info!("回填 live 提示词内容到已启用项: {enabled_id}");
+                        drop(cfg); // 释放锁后保存，避免死锁
+                        state.save()?; // 第一次保存：回填后立即持久化
+                    } else {
+                        // 没有已启用的提示词，则创建一次备份（避免重复备份）
+                        let content_exists = prompts
+                            .values()
+                            .any(|p| p.content.trim() == live_content.trim());
                         if !content_exists {
                             let timestamp = std::time::SystemTime::now()
                                 .duration_since(std::time::UNIX_EPOCH)
@@ -105,21 +116,26 @@ impl PromptService {
                                     "原始提示词 {}",
                                     chrono::Local::now().format("%Y-%m-%d %H:%M")
                                 ),
-                                content,
+                                content: live_content,
                                 description: Some("自动备份的原始提示词".to_string()),
                                 enabled: false,
                                 created_at: Some(timestamp),
                                 updated_at: Some(timestamp),
                             };
-                            prompts.insert(backup_id, backup_prompt);
+                            prompts.insert(backup_id.clone(), backup_prompt);
+                            log::info!("回填 live 提示词内容，创建备份: {backup_id}");
+                            drop(cfg); // 释放锁后保存
+                            state.save()?; // 第一次保存：回填后立即持久化
+                        } else {
+                            // 即使内容已存在，也无需重复备份；但不需要保存任何更改
+                            drop(cfg);
                         }
                     }
                 }
             }
-            drop(cfg);
         }
 
-        // 启用目标提示词
+        // 启用目标提示词并写入文件
         let mut cfg = state.config.write()?;
         let prompts = match app {
             AppType::Claude => &mut cfg.prompts.claude.prompts,
@@ -133,13 +149,13 @@ impl PromptService {
 
         if let Some(prompt) = prompts.get_mut(id) {
             prompt.enabled = true;
-            write_text_file(&target_path, &prompt.content)?;
+            write_text_file(&target_path, &prompt.content)?; // 原子写入
         } else {
             return Err(AppError::InvalidInput(format!("提示词 {id} 不存在")));
         }
 
         drop(cfg);
-        state.save()?;
+        state.save()?; // 第二次保存：启用目标提示词并写入文件后
         Ok(())
     }