Slices catch their own mistakes earlier

Trau catches more of its own mistakes before it calls a slice done: changed tests must pass before verification, and what one slice learns passes to its siblings.

Added

Trau runs the tests a slice promised and touched before verification, sending failures straight back to repair
The build phase works to a checklist of the defects that come back most often, so they are caught while the code is written
Screenshots from browser checks are always attached to the run instead of sometimes being dropped
A slice inherits what its sibling slices in the same epic just learned

Changed

Updates, push notifications and external agents move from Settings to a new Hub page

Removed

The floating interview dock is gone; interview questions arrive as notifications that open the right conversation