ECC community plugin pruning: removed 530+ non-essential files (.cursor/, .opencode/, docs/ja-JP, docs/zh-CN, docs/zh-TW, language-specific skills/agents/rules). Retained 4 agents, 3 commands, 5 skills. Promoted 13 rule files (8 common + 5 typescript) to .claude/rules/ for CC native loading. Extracted reusable patterns to EXTRACTED-PATTERNS.md.