feat: add cloud-solution-architect skill

[thegovind]

Summary

Add a new cloud-solution-architect core skill for designing well-architected Azure cloud systems, based on the Azure Architecture Center.

What's Included

SKILL.md (317 lines)

• 10 design principles for Azure applications
• 6 architecture styles with selection criteria
• 44 cloud design patterns organized by concern and mapped to WAF pillars
• Technology choice frameworks (compute, storage, data, messaging, networking, AI, containers)
• 12 best practices for cloud applications
• 10 performance antipatterns to avoid
• Mission-critical design overview (99.99%+ SLO)
• Well-Architected Framework 5-pillar tradeoff matrix
• 7-step architecture review workflow with ADR template

Progressive Discovery (8 reference files, ~3,000 lines)

Reference	Lines	Content
design-patterns.md	873	All 44 patterns with problem/when-to-use/WAF pillars
acceptance-criteria.md	436	Test acceptance criteria
architecture-styles.md	365	6 styles with ASCII diagrams and tradeoffs
design-principles.md	328	All 10 principles with recommendations
best-practices.md	311	12 practices with WAF alignment
mission-critical.md	285	High-availability design areas
performance-antipatterns.md	242	10 antipatterns with detection/fixes
technology-choices.md	159	Decision tables for Azure services

Tests

• 8 test scenarios covering: architecture review, design pattern selection, technology choices, WAF assessment, mission-critical design, performance antipattern detection, scalability design, event-driven architecture

Documentation Updates

• README.md: Core skill count 7→8, new skill added alphabetically to catalog
• skills.json: Regenerated for GitHub Pages (auto-picked up by extract-skills.ts)

Source

All content derived from the Azure Architecture Center — Microsoft's official cloud architecture guidance.