fix(chat): count a subagent's edits in the turn's Edited N files card (#86)

A skill that hands its work to subagents (vp-auto) showed "Edited 1 file"
for a turn that changed 4: a subagent's Write/Edit calls are in its own
agent-<id>.jsonl, so the card only saw the parent's.

- server/lib/agent-edits.js reads a subagent's transcript (readLines, a
  member's only as theirs) for the files it wrote or edited with their +/-
  lines, nested subagents folded in (3 levels), cached by size + mtime.
- The transcript route puts them on each Claude Agent/Task result as
  `edits`; the card adds them to the turn's own edits. A file only a
  subagent wrote is listed, never an artifact card (its versions are
  rebuilt from this transcript's inputs, which a subagent's are not).

client/src/components/conversation/MessageList.tsx

@@ -491,6 +491,8 @@ type Item =
   | { kind: "command"; key: string; name: string | null; output: string | null; error: boolean };
 
 const EDIT_TOOLS = new Set(["Write", "Edit", "MultiEdit", "NotebookEdit"]);
+// A subagent's result carries the files IT changed (`edits`): they count too.
+const AGENT_TOOLS = new Set(["Agent", "Task"]);
 
 /** A line that is only Claude Code's local-command plumbing — the caveat it
  *  writes first, the command, what the command printed — or null for
@@ -592,7 +594,11 @@ export function chatItems(messages: TranscriptMessage[], keys: string[]): Item[]
     if (msg.usage) output.add(msg.usage);
     msg.content.forEach((block, b) => {
       const last = items[items.length - 1];
-      if (block.type === "tool_use" && EDIT_TOOLS.has(block.name ?? "")) edits.push(block);
+      if (
+        block.type === "tool_use" &&
+        (EDIT_TOOLS.has(block.name ?? "") || AGENT_TOOLS.has(block.name ?? ""))
+      )
+        edits.push(block);
       // A question to the user is a turn of the conversation, not hidden work.
       if (block.type === "tool_use" && block.name === "AskUserQuestion") {
         items.push({ kind: "ask", key: `${key}:${b}`, block });
@@ -672,19 +678,38 @@ function EditedFilesCard({
   const files = new Map<string, { added: number; removed: number; counted: boolean }>();
   // Written whole in this turn (a Write): a component made here is an artifact.
   const created = new Set<string>();
+  // Changed only by a subagent: listed, never an artifact card — the chat
+  // rebuilds an artifact from this transcript's Write/Edit inputs, which a
+  // subagent's are not.
+  const byAgent = new Set<string>();
   for (const b of blocks) {
+    const r0 = b.id ? toolResultMap.get(b.id) : undefined;
+    if (AGENT_TOOLS.has(b.name ?? "")) {
+      for (const e of r0?.edits ?? []) {
+        if (!files.has(e.path)) byAgent.add(e.path);
+        const f = files.get(e.path) ?? { added: 0, removed: 0, counted: false };
+        f.added += e.added;
+        f.removed += e.removed;
+        f.counted ||= e.counted;
+        files.set(e.path, f);
+      }
+      continue;
+    }
     const input = (b.input ?? {}) as Record<string, unknown>;
     const p = input.file_path ?? input.notebook_path;
     const r = b.id ? toolResultMap.get(b.id) : undefined;
     if (typeof p !== "string" || !r || r.is_error) continue;
     if (b.name === "Write") created.add(p);
+    byAgent.delete(p);
     const f = files.get(p) ?? { added: 0, removed: 0, counted: false };
     f.added += r.diff?.added ?? 0;
     f.removed += r.diff?.removed ?? 0;
     f.counted ||= !!r.diff;
     files.set(p, f);
   }
-  const artifacts = [...files.keys()].filter((p) => isArtifact(p, created.has(p)));
+  const artifacts = [...files.keys()].filter(
+    (p) => !byAgent.has(p) && isArtifact(p, created.has(p))
+  );
   const cards = artifacts.length > 0 && (
     <div data-testid="artifact-cards" className="flex flex-col gap-2">
       {artifacts.map((p) => (

client/src/components/conversation/__tests__/MessageList.edits.test.tsx

@@ -4,7 +4,9 @@
  * Desktop's "Edited N files" card: one row per file with the lines added and
  * removed summed over the turn, a failed call left out, a row click handed
  * to the caller, and a row (or the header, every file) dragged as `@path`
- * attachments for a prompt box.
+ * attachments for a prompt box. Files a subagent changed (its Agent
+ * result's `edits`, read from its own transcript) are counted in the same
+ * card, never as an artifact.
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 import { describe, it, expect, vi } from "vitest";
@@ -127,4 +129,49 @@ describe("the Edited N files card", () => {
       JSON.parse(all["application/x-agenthub-attach"]!).map((a: { path: string }) => a.path)
     ).toEqual(["@/w/a.ts", "@/w/b.json"]);
   });
+
+  it("counts the files a subagent changed, beside the turn's own edits", () => {
+    render(
+      <MessageList
+        loading={false}
+        messages={[
+          user("run the task"),
+          call("1", "Edit", "/w/a.go"),
+          result("1", { added: 1, removed: 0 }),
+          {
+            type: "assistant",
+            sender: "assistant",
+            timestamp: at,
+            content: [{ type: "tool_use", id: "2", name: "Agent", input: { prompt: "do it" } }],
+          } as TranscriptMessage,
+          {
+            type: "user",
+            sender: "tool",
+            timestamp: at,
+            content: [
+              {
+                type: "tool_result",
+                id: "2",
+                output: "done",
+                agent: { id: "x1" },
+                edits: [
+                  { path: "/w/a.go", added: 4, removed: 2, counted: true },
+                  { path: "/w/b_test.go", added: 9, removed: 0, counted: true },
+                  { path: "/w/report.html", added: 5, removed: 0, counted: true },
+                ],
+              },
+            ],
+          } as TranscriptMessage,
+          user("thanks"),
+        ]}
+      />
+    );
+    const card = screen.getByTestId("edited-files");
+    expect(card.textContent).toContain("Edited 3 files");
+    expect(within(card).getByText("b_test.go")).toBeTruthy();
+    expect(within(card).getByTitle("/w/a.go").textContent).toContain("+5"); // a.go: 1 + 4
+    // A page only a subagent wrote is listed, not shown as an artifact card.
+    expect(within(card).getByText("report.html")).toBeTruthy();
+    expect(screen.queryByTestId("artifact-card")).toBeNull();
+  });
 });

client/src/lib/types.ts

@@ -3236,6 +3236,10 @@ export interface TranscriptContent {
   /** Present on a Write/Edit/MultiEdit "tool_result": the lines it added and
    *  removed (from Claude Code's `structuredPatch`). */
   diff?: { added: number; removed: number };
+  /** Present on an Agent/Task "tool_result" whose subagent (or one it started)
+   *  wrote or edited files: each file with its +/- lines (`counted`: the
+   *  results carried them). Read from the subagent's own transcript. */
+  edits?: { path: string; added: number; removed: number; counted: boolean }[];
   /** Present on an AskUserQuestion "tool_result": question text → the option
    *  the user picked, or what they typed. */
   answers?: Record<string, string>;