Proposal: Remove all non-done FR entries from locked list

Only vault/10_features/06_done should be locked. All individual FR entries from 02_new, 03_planned, 04_in-progress, and 05_review should be removed.

Change

Replace all individual FR entries (lines 19-73) with just:

  - vault/10_features/06_done

This removes ~53 individual FR entries and the redundant 06_done/FR-001 and 06_done/FR-002 entries (already covered by the directory entry).