fix(usage): count Claude Code Workflow sub-agent token usage

collect_jsonl_files only walked <project>/<session>/subagents/*.jsonl,
so it missed Workflow sub-agent transcripts which live one level deeper
at subagents/workflows/wf_*/agent-*.jsonl. As a result all Workflow
token usage was invisible to the no-proxy session-log accounting.

Descend into subagents/workflows/wf_*/ as well, via a new
push_jsonl_children helper that keeps the fixed-depth, no-recursion
design. journal.jsonl carries no assistant rows so it is skipped at
parse time and needs no filename special-casing. Existing dedup
(request_id PK + INSERT OR IGNORE + should_skip_session_insert) keeps
the next sync's backfill idempotent.

Add test_collect_jsonl_files_includes_workflow_subagents.

src-tauri/src/services/session_usage.rs

@@ -109,9 +109,15 @@ pub fn sync_claude_session_logs(db: &Database) -> Result<SessionSyncResult, AppE
 
 /// 收集目录下所有 .jsonl 文件（含子 agent 文件）
 ///
-/// 扫描三层固定深度，不使用递归，避免死循环：
-///   projects_dir/项目目录/*.jsonl                          (主会话)
-///   projects_dir/项目目录/SESSION_ID/subagents/*.jsonl      (子 agent)
+/// 扫描固定深度，不使用递归，避免死循环：
+///   projects_dir/项目目录/*.jsonl                                      (主会话)
+///   projects_dir/项目目录/SESSION_ID/subagents/*.jsonl                  (Task/Agent 子 agent)
+///   projects_dir/项目目录/SESSION_ID/subagents/workflows/wf_*/*.jsonl   (Workflow 子 agent)
+///
+/// 最后一层是 Claude Code Workflow 功能产生的子 agent transcript，比普通子
+/// agent 多嵌套一层 `workflows/wf_<ID>/`。漏掉这一层会让 Workflow 的 token
+/// 用量完全不计入统计；`journal.jsonl` 不含 `type=="assistant"` 行，解析时
+/// 会被 `sync_single_file` 天然跳过，因此这里无需按文件名过滤。
 fn collect_jsonl_files(projects_dir: &Path) -> Vec<PathBuf> {
     let mut files = Vec::new();
 
@@ -136,12 +142,18 @@ fn collect_jsonl_files(projects_dir: &Path) -> Vec<PathBuf> {
                     // 扫描子 agent 目录: 项目/SESSION_ID/subagents/*.jsonl
                     let subagents_dir = sub_path.join("subagents");
                     if subagents_dir.is_dir() {
-                        if let Ok(agent_entries) = fs::read_dir(&subagents_dir) {
-                            for agent_entry in agent_entries.flatten() {
-                                let agent_path = agent_entry.path();
-                                if agent_path.extension().and_then(|e| e.to_str()) == Some("jsonl")
-                                {
-                                    files.push(agent_path);
+                        push_jsonl_children(&subagents_dir, &mut files);
+
+                        // 额外下探 Workflow 子 agent:
+                        // 项目/SESSION_ID/subagents/workflows/wf_<ID>/*.jsonl
+                        let workflows_dir = subagents_dir.join("workflows");
+                        if workflows_dir.is_dir() {
+                            if let Ok(wf_entries) = fs::read_dir(&workflows_dir) {
+                                for wf_entry in wf_entries.flatten() {
+                                    let wf_path = wf_entry.path();
+                                    if wf_path.is_dir() {
+                                        push_jsonl_children(&wf_path, &mut files);
+                                    }
                                 }
                             }
                         }
@@ -154,6 +166,18 @@ fn collect_jsonl_files(projects_dir: &Path) -> Vec<PathBuf> {
     files
 }
 
+/// 将 `dir` 下直接子层的所有 `.jsonl` 文件追加到 `files`（不递归）。
+fn push_jsonl_children(dir: &Path, files: &mut Vec<PathBuf>) {
+    if let Ok(entries) = fs::read_dir(dir) {
+        for entry in entries.flatten() {
+            let path = entry.path();
+            if path.extension().and_then(|e| e.to_str()) == Some("jsonl") {
+                files.push(path);
+            }
+        }
+    }
+}
+
 /// 同步单个 JSONL 文件，返回 (imported, skipped)
 fn sync_single_file(db: &Database, file_path: &Path) -> Result<(u32, u32), AppError> {
     let file_path_str = file_path.to_string_lossy().to_string();
@@ -685,4 +709,39 @@ mod tests {
 
         fs::remove_dir_all(&tmp).ok();
     }
+
+    #[test]
+    fn test_collect_jsonl_files_includes_workflow_subagents() {
+        // Claude Code Workflow 把子 agent transcript 嵌在
+        // 项目/SESSION_ID/subagents/workflows/wf_<ID>/ 下，比普通子 agent 深一层。
+        let tmp = std::env::temp_dir().join(format!("cc-switch-test-{}", uuid::Uuid::new_v4()));
+        let project = tmp.join("project");
+        let session_dir = project.join("test-session");
+        let subagents_dir = session_dir.join("subagents");
+        let wf_dir = subagents_dir.join("workflows").join("wf_test123");
+        fs::create_dir_all(&wf_dir).unwrap();
+
+        fs::write(project.join("main.jsonl"), "{}").unwrap();
+        fs::write(subagents_dir.join("agent-plain.jsonl"), "{}").unwrap();
+        fs::write(wf_dir.join("agent-wf.jsonl"), "{}").unwrap();
+        // journal.jsonl 也会被收集，但解析时因无 assistant 行而产出 0 条
+        fs::write(wf_dir.join("journal.jsonl"), "{}").unwrap();
+
+        let files = collect_jsonl_files(&tmp);
+        let paths: Vec<String> = files
+            .iter()
+            .map(|p| p.to_string_lossy().to_string())
+            .collect();
+
+        // 主会话 + 普通子 agent + Workflow 子 agent(agent-wf + journal) = 4
+        assert_eq!(files.len(), 4);
+        assert!(paths.iter().any(|p| p.contains("main.jsonl")));
+        assert!(paths.iter().any(|p| p.contains("agent-plain.jsonl")));
+        assert!(
+            paths.iter().any(|p| p.contains("agent-wf.jsonl")),
+            "Workflow 子 agent transcript 必须被收集"
+        );
+
+        fs::remove_dir_all(&tmp).ok();
+    }
 }