Move installingApps from local refs in Marketplace/Discover to the
global server store. Install progress now persists when navigating
between views. My Apps shows installing overlay with progress bar
for apps being installed from the Marketplace.
Changes:
- server.ts: add installingApps Map + helpers to store
- Marketplace.vue: use store's installingApps instead of local ref
- Discover.vue: same
- Apps.vue: pass isInstalling + installProgress to AppCard
- AppCard.vue: add amber installing overlay with progress bar
522 tests pass, vue-tsc clean.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
