feat(desktop): render rich tool activity cards

.qwen/e2e-tests/electron-desktop/rich-tool-call-activity-cards.md

@@ -0,0 +1,47 @@
+# Rich Tool-Call Activity Cards
+
+- Slice date: 2026-04-26
+- Executable harness: `packages/desktop/scripts/e2e-cdp-smoke.mjs`
+- Command:
+  `cd packages/desktop && npm run e2e:cdp`
+- Result: pass
+- Artifact directory:
+  `.qwen/e2e-tests/electron-desktop/artifacts/2026-04-25T17-57-31-788Z/`
+
+## Scenario
+
+1. Launch the real Electron app with isolated HOME, runtime, user-data, and a
+   fake dirty Git workspace.
+2. Open the fake project through the desktop directory picker path.
+3. Send the first composer prompt and approve the fake command request.
+4. Wait for the fake ACP resolved tool update.
+5. Assert the conversation renders a compact tool activity card with command
+   title, status, command input, output summary, and file chip.
+6. Continue the existing changed-files, review, settings, terminal, and final
+   layout smoke path.
+
+## Assertions
+
+- The resolved activity card is inside the chat timeline and stays above the
+  composer without overlap.
+- The card includes `Run desktop E2E command`, `completed`,
+  `printf desktop-e2e`, `desktop-e2e command completed`, and `README.md:1`.
+- The card does not show the fake tool call ID or session ID.
+- Legacy `.chat-tool` rows are absent.
+- Console errors: 0.
+- Failed local network requests: 0.
+
+## Artifacts
+
+- `resolved-tool-activity.json`
+- `resolved-tool-activity.png`
+- `conversation-changes-summary.json`
+- `completed-workspace.png`
+- `electron.log`
+- `summary.json`
+
+## Known Uncovered Risk
+
+The harness covers deterministic fake ACP tool updates with one file reference
+and bounded string output. Live ACP tools with richer structured outputs, many
+file references, and long command output still need broader coverage.