Live share links — auto-updating public view

v4 introduced frozen share snapshots. v5 adds a **live mode** that auto-updates as the project changes.

Creating a live link:
1. Open Overview → Share view link
2. In the modal, set **Mode** = "Live — auto-updates as the project changes"
3. Pick scope + expiry as usual
4. Click Generate link

What's different from frozen:
• The token doc only carries metadata (no embedded snapshot)
• Each time someone opens the link, a Cloud Function (`getLiveProjectShare`) reads the current project state and returns a fresh view
• Reload the page to see the latest data

When to use which:
• **Frozen** — pinning a status report to send via email; want the recipient to see exactly what you saw at send-time
• **Live** — embedding in a stakeholder portal where they should always see the latest

Both modes:
• Use the same unguessable URL pattern (`/p/share/<token>`)
• Honour the same expiry + revocation rules
• Track view count