v1.5.2 — Download UX for AI Agents

Improved

• Download metadata now includes contentUrl for direct file retrieval by AI agents
• Default download TTL increased from 30 minutes to 24 hours
• Download registry persisted to disk (registry.json) — survives server restarts
• TTL countdown starts from completedAt instead of createdAt
• Orphaned download files automatically rebuilt into registry on startup
• Updated AGENTS.md with clear download workflow guide for AI agents

Fixed

• finalizeDownload failure branch now persists registry state
• Click handler download response now includes contentUrl
• buildContentUrl exported and reused across modules (DRY)

For AI Agents

Every download response now includes contentUrl — just GET it to retrieve the binary file.