feat: add 33 skills from vudovn/antigravity-kit

- Added: api-patterns, app-builder, architecture, bash-linux, behavioral-modes,
  clean-code, code-review-checklist, database-design, deployment-procedures,
  docker-expert, documentation-templates, game-development, geo-fundamentals,
  i18n-localization, lint-and-validate, mobile-design, nestjs-expert,
  nextjs-best-practices, nodejs-best-practices, parallel-agents,
  performance-profiling, plan-writing, powershell-windows, prisma-expert,
  python-patterns, react-patterns, red-team-tactics, seo-fundamentals,
  server-management, tailwind-patterns, tdd-workflow, typescript-expert,
  vulnerability-scanner
- Updated README: skill count 179 → 223
- Added credit for vudovn/antigravity-kit (MIT License)

Source: https://github.com/vudovn/antigravity-kit

skills/architecture/trade-off-analysis.md

@@ -0,0 +1,77 @@
+# Trade-off Analysis & ADR
+
+> Document every architectural decision with trade-offs.
+
+## Decision Framework
+
+For EACH architectural component, document:
+
+```markdown
+## Architecture Decision Record
+
+### Context
+- **Problem**: [What problem are we solving?]
+- **Constraints**: [Team size, scale, timeline, budget]
+
+### Options Considered
+
+| Option | Pros | Cons | Complexity | When Valid |
+|--------|------|------|------------|-----------|
+| Option A | Benefit 1 | Cost 1 | Low | [Conditions] |
+| Option B | Benefit 2 | Cost 2 | High | [Conditions] |
+
+### Decision
+**Chosen**: [Option B]
+
+### Rationale
+1. [Reason 1 - tied to constraints]
+2. [Reason 2 - tied to requirements]
+
+### Trade-offs Accepted
+- [What we're giving up]
+- [Why this is acceptable]
+
+### Consequences
+- **Positive**: [Benefits we gain]
+- **Negative**: [Costs/risks we accept]
+- **Mitigation**: [How we'll address negatives]
+
+### Revisit Trigger
+- [When to reconsider this decision]
+```
+
+## ADR Template
+
+```markdown
+# ADR-[XXX]: [Decision Title]
+
+## Status
+Proposed | Accepted | Deprecated | Superseded by [ADR-YYY]
+
+## Context
+[What problem? What constraints?]
+
+## Decision
+[What we chose - be specific]
+
+## Rationale
+[Why - tie to requirements and constraints]
+
+## Trade-offs
+[What we're giving up - be honest]
+
+## Consequences
+- **Positive**: [Benefits]
+- **Negative**: [Costs]
+- **Mitigation**: [How to address]
+```
+
+## ADR Storage
+
+```
+docs/
+└── architecture/
+    ├── adr-001-use-nextjs.md
+    ├── adr-002-postgresql-over-mongodb.md
+    └── adr-003-adopt-repository-pattern.md
+```