# Manual smoke — F7 rendered track-changes preview (#21)

The webview's *visual* rendering (mermaid, theming) is verified here, not in the
automated host E2E (the webview is a sealed sandbox — §6.8). Run once per change
that touches F7.

## Setup

1. `npm run build`
2. Launch the Extension Development Host (F5 in VS Code, or the Run panel).
3. Open a folder and a markdown document containing prose, a `mermaid` fenced
   diagram, and a `ts` code fence (e.g. copy
   `test/e2e/fixtures/workspace/docs/preview.md`).

## Steps

1. **Open the preview.** Run **"Cowriting: Open Track-Changes Preview"** (or
   `Ctrl+Alt+R`). A preview opens beside the editor, rendering the document.
   Header reads `Track changes since opened …`, summary `+0 −0`. The mermaid
   diagram renders as a diagram; the code fence renders as highlighted code.
2. **Edit prose.** In the source editor, change a word in a paragraph. The
   preview updates (≈150 ms): the old word struck (`<del>`), the new word
   highlighted (`<ins>`); the summary increments.
3. **Edit the mermaid.** Change `a --> b` to `a --> c`. The preview re-renders the
   **new** diagram with a **"changed"** badge at its top-right.
4. **Ask Claude + accept.** Select the target sentence → "Ask Claude to Edit
   Selection" → accept the proposal. The accepted text **drops its marks** (the
   baseline advanced; PUC-3).
5. **Pin.** Run "Cowriting: Pin Diff Baseline to Now". All marks clear (baseline
   == now; PUC-4).
6. **Theme.** Toggle light/dark (`Ctrl+K Ctrl+T`). Marks and the diagram restyle
   to the theme.
7. **Cleanliness.** `git status` shows nothing changed by the preview (INV-20).

## Pass criteria

All seven steps behave as described; no console errors in the webview devtools;
nothing written to the document, sidecar, or repo.