Add Caps Lock indicator LED config commands

[Vitnir]

Draft implementation for a configurable Caps Lock LED indicator.

Discussion:

• Caps Lock LED indicator for Defy/Raise Bazecor#1126

This adds persistent LEDManager configuration and Focus commands:

• led.capsLockIndicator.enabled
• led.capsLockIndicator.color

Scope:

• configuration storage
• Focus read/write commands
• help discovery for UI feature gating

Not included yet:

• live host Caps Lock state handling
• LED overlay rendering on the physical Caps Lock key

Those parts likely need the keyboard/keymap adapter APIs from the Defy firmware stack.