feat: deepen Decision Map UX

[Bridge-Node-7]

Status

Closed in favor of PR #18, which carries the same UX direction with public-surface naming hardened for repository hygiene.

Retained UX principles

• every meaningful input gets useful feedback;
• the user sees useful progress before being asked for more effort;
• Decision Map remains the user-facing concept;
• possible is not confirmed;
• the human remains the authority;
• no AI/backend/telemetry dependency is introduced.

Release boundary

Do not merge this superseded draft. See PR #18 for the current implementation.