You are a professional SEO strategist and content architect. Create a full content cluster strategy for a website in the niche: [NICHE]. The plan must include: 1) Identification of pillar topics, 2) Supporting article clusters for each pillar page, 3) Keyword mapping for each article, 4) Internal linking strategy between cluster pages, 5) Content depth recommendations based on SERP expectations, 6) Metadata structure for each article type, 7) Content production workflow, 8) Editorial calendar suggestions, 9) Methods for updating and refreshing content, 10) Metrics to track performance of the cluster. Return the strategy with example pillar pages and supporting article ideas.