Accessibility: NO_COLOR, non-TTY, screen reader audit

Audit the CLI surface for accessibility: `NO_COLOR` honored, non-TTY
output sensible, `IInteractionService` output friendly to screen
readers.

## Definition of Done

- [ ] `NO_COLOR` audit complete
- [ ] Non-TTY audit complete
- [ ] Screen-reader review of key flows
- [ ] Gaps tracked + fixed

Start by locating the CLI surface and the IInteractionService, then inspect key flows under NO_COLOR and non-TTY conditions. Audit output for sensible terminal behavior and screen-reader compatibility; done means the three audits are complete and every identified gap is tracked and fixed.

Written by the indexing model from the issue text.