/forge-harmonize — Add Harmony Color

From the brand color, compute:

• Complementary: 180° hue rotation
• Split-complementary: ±150° hue rotation
• Analogous: ±30° hue rotation
• Triadic: ±120° hue rotation

Suggest the best option based on project type:

• SaaS: complementary (clear differentiation)
• Portfolio: analogous (cohesive mood)
• E-commerce: split-complementary (attention without clash)
• Docs: analogous (calm, readable)

Generate a secondary palette and add to .forge.json.