Make Creator Micro session slots activity-aware

[edwin-zvs]

Summary

• map the six session buttons to the six most recently active eligible sessions while preserving surviving physical-slot assignments
• focus an already-visible mapped session in place; otherwise open it in the currently focused pane
• map ACT06–ACT09 to visible split panes 1–4 and ACT10–ACT12 to Yes, No, and Enter
• document the revised layout, stable-slot semantics, and independent-keycap requirement

Verification

• cargo test -p construct-cli --bin construct creator_micro (10 passed)
• cargo build

A broad CLI test run inside the workspace sandbox encountered unrelated environment failures: mock-daemon socket binds were denied with Operation not permitted. The focused Creator Micro suite is green.