feat: add customer-research skill

[coreyhaines31]

Add a new customer-research skill covering:

• Analyzing existing research assets (video transcripts, survey results, support conversations, sales call notes)
• Digital watering hole research (Reddit, G2, forums, communities, review sites, blog posts)
• Synthesizing findings into insights, patterns, and themes
• Generating customer personas from research
• Sentiment analysis and VOC (voice of customer) extraction

Trigger phrases: 'customer research', 'ICP research', 'talk to customers', 'analyze transcripts', 'build personas', 'what do customers say', 'Reddit mining', 'G2 reviews', 'voice of customer', 'VOC'

[coreyhaines31]

Already shipped! The customer-research skill was added in v1.5.0.