Apply valueColor to percentage values instead of headerColor

[akasai]

Summary

• Use valueColor option for percentage display instead of headerColor
• Previously, headerColor (fg) was applied to both labels (Session, Weekly, etc.) and percentage values when usage was below 51%
• Now headerColor only applies to labels, and valueColor applies to percentage values as the base color
• High-usage color gradient (orange at 51%+, deep orange at 80%+) is preserved

Before / After

Element	Before	After
Labels (Session, Weekly…)	headerColor	headerColor (unchanged)
Percentage (< 51%)	headerColor	valueColor
Percentage (51-79%)	#F0A875	#F0A875 (unchanged)
Percentage (≥ 80%)	CLAUDE_ORANGE	CLAUDE_ORANGE (unchanged)
Reset time	dimColor	dimColor (unchanged)

[stevejkang]

LGTM