F14.2c — Show a semantic numbered guide palette and progress

[Flow-Fly]

Parent: #130. Depends on #311.

Replace palette editing controls with creative guidance while a guided session is active.

Acceptance:

• Guide colors are semantic keyboard-reachable buttons with stable 1..N badges.
• Each guide color exposes its remaining count and current selection state without relying on color alone.
• Show covered, remaining, and percentage as informational progress, never as correctness.
• Extra colors created by free drawing remain selectable as unnumbered artist colors.
• The normal editable palette remains unchanged for ordinary projects.

[Flow-Fly]

Completed in PR #315. The implementation is merged into develop at a9ed5f9 and post-merge CI run 29086892806 passed.