v1.70.1: Launch Hardening

Changelog

• ac77eee Honor SWITCHTENDER_AUDIT_KEY on a no-home install
• 4ec6d0a Keep the overrun sweep off split and pipeline parents
• 5df720f Let the host, tasks, and compare pages filter the column they are built on
• f1e2ed4 Let viewers and operators open the live run view
• 35286f7 Make the marketing header reachable on mobile and refresh stale assets
• 202fcbe Mask credentials embedded in URLs on every disclosure path
• 5ae9486 Polish the empty states, timestamps, and thin columns across the app
• 3b8e74f Refuse the chain shapes the reference verifier refuses
• 7eff38c Show what a run actually ran: commit, queue, image, and when
• 8fceab9 Stop the age timer from deleting every copy-timestamp button