feat(app): add weekly recap cards with swipeable story UI and export

Introduce a Spotify-Wrapped-style recap feature: five themed cards
  (Cover, Path, Vibe, Workflow, Closing) rendered per archetype palette,
  with keyboard/swipe navigation and image export via capture IPC. Add
  RecapList, RecapDetail, RecapExport views and recap component library.
  Wire recap:list/read/updated IPC channels through preload, document the
  retrieval-to-card contract in references/recap-patterns.md, and bundle
  dist-renderer for production use.

app/preload.js

@@ -24,4 +24,13 @@ contextBridge.exposeInMainWorld('obelisk', {
     ipcRenderer.on('obelisk:index-updated', listener);
     return () => ipcRenderer.removeListener('obelisk:index-updated', listener);
   },
+  captureExport: (opts) => ipcRenderer.invoke('capture:export', opts),
+  copyImage: (opts) => ipcRenderer.invoke('capture:copy', opts),
+  recapList: () => ipcRenderer.invoke('recap:list'),
+  recapRead: (filename) => ipcRenderer.invoke('recap:read', filename),
+  onRecapUpdated: (callback) => {
+    const listener = (_, filePath) => callback(filePath);
+    ipcRenderer.on('obelisk:recap-updated', listener);
+    return () => ipcRenderer.removeListener('obelisk:recap-updated', listener);
+  },
 });