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/code-review-checklist/SKILL.md

@@ -0,0 +1,109 @@
+---
+name: code-review-checklist
+description: Code review guidelines covering code quality, security, and best practices.
+allowed-tools: Read, Glob, Grep
+---
+
+# Code Review Checklist
+
+## Quick Review Checklist
+
+### Correctness
+- [ ] Code does what it's supposed to do
+- [ ] Edge cases handled
+- [ ] Error handling in place
+- [ ] No obvious bugs
+
+### Security
+- [ ] Input validated and sanitized
+- [ ] No SQL/NoSQL injection vulnerabilities
+- [ ] No XSS or CSRF vulnerabilities
+- [ ] No hardcoded secrets or sensitive credentials
+- [ ] **AI-Specific:** Protection against Prompt Injection (if applicable)
+- [ ] **AI-Specific:** Outputs are sanitized before being used in critical sinks
+
+### Performance
+- [ ] No N+1 queries
+- [ ] No unnecessary loops
+- [ ] Appropriate caching
+- [ ] Bundle size impact considered
+
+### Code Quality
+- [ ] Clear naming
+- [ ] DRY - no duplicate code
+- [ ] SOLID principles followed
+- [ ] Appropriate abstraction level
+
+### Testing
+- [ ] Unit tests for new code
+- [ ] Edge cases tested
+- [ ] Tests readable and maintainable
+
+### Documentation
+- [ ] Complex logic commented
+- [ ] Public APIs documented
+- [ ] README updated if needed
+
+## AI & LLM Review Patterns (2025)
+
+### Logic & Hallucinations
+- [ ] **Chain of Thought:** Does the logic follow a verifiable path?
+- [ ] **Edge Cases:** Did the AI account for empty states, timeouts, and partial failures?
+- [ ] **External State:** Is the code making safe assumptions about file systems or networks?
+
+### Prompt Engineering Review
+```markdown
+// ❌ Vague prompt in code
+const response = await ai.generate(userInput);
+
+// ✅ Structured & Safe prompt
+const response = await ai.generate({
+  system: "You are a specialized parser...",
+  input: sanitize(userInput),
+  schema: ResponseSchema
+});
+```
+
+## Anti-Patterns to Flag
+
+```typescript
+// ❌ Magic numbers
+if (status === 3) { ... }
+
+// ✅ Named constants
+if (status === Status.ACTIVE) { ... }
+
+// ❌ Deep nesting
+if (a) { if (b) { if (c) { ... } } }
+
+// ✅ Early returns
+if (!a) return;
+if (!b) return;
+if (!c) return;
+// do work
+
+// ❌ Long functions (100+ lines)
+// ✅ Small, focused functions
+
+// ❌ any type
+const data: any = ...
+
+// ✅ Proper types
+const data: UserData = ...
+```
+
+## Review Comments Guide
+
+```
+// Blocking issues use 🔴
+🔴 BLOCKING: SQL injection vulnerability here
+
+// Important suggestions use 🟡
+🟡 SUGGESTION: Consider using useMemo for performance
+
+// Minor nits use 🟢
+🟢 NIT: Prefer const over let for immutable variable
+
+// Questions use ❓
+❓ QUESTION: What happens if user is null here?
+```