Leader Key: Add visual menu overlay (expectation mismatch)

[malpern]

Problem

Users expect Mac "leaderkey" app behavior (visual menu overlay) but KeyPath provides a momentary layer activator.

Expected Behavior

1. Press leader key → See visual menu showing available shortcuts
2. Overlay displays all mapped key combinations
3. Visual feedback while typing sequence
4. Can press a key to trigger that action

Actual Implementation

• Momentary layer activator (hold-to-activate pattern)
• No visual overlay
• No sequence display
• No live key menu

Impact

User confusion - users expect visual menu system but get layer activation.

Options

A. Add visual overlay when leader is held (shows available layer shortcuts)
B. Document clearly that this is NOT a visual menu system
C. Build separate "Leader Menu" feature matching expected behavior

References

• RuleCollectionCatalog.swift lines 100-142
• LauncherCollectionView.swift lines 10-186 (closest to expected UI)
• Comprehensive review: docs/code-review/comprehensive-feature-review.md