Added AI skills

.agents/skills/zod/README.md

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+# Zod Best Practices Skill
+
+A comprehensive guide for using Zod effectively in TypeScript applications. This skill provides 42 rules across 8 categories, organized by impact to help AI agents and developers write better validation code.
+
+## Overview
+
+Zod is a TypeScript-first schema declaration and validation library. This skill covers best practices for:
+
+- **Schema Definition**: Choosing correct types, avoiding `z.any()`, proper string validations
+- **Parsing & Validation**: Using `safeParse()`, async validation, error handling
+- **Type Inference**: Leveraging `z.infer`, distinguishing input/output types
+- **Error Handling**: Custom messages, internationalization, form error display
+- **Object Schemas**: strict/strip modes, partial updates, discriminated unions
+- **Schema Composition**: Reusable schemas, intersections, recursive types
+- **Refinements & Transforms**: Custom validation, data transformation
+- **Performance**: Caching, Zod Mini, lazy loading, batch validation
+
+## Usage
+
+### For Claude Code / AI Agents
+
+The skill is automatically loaded when working with Zod code. Reference specific rules:
+
+```
+See rules/parse-use-safeparse.md for safeParse best practices
+```
+
+### For Developers
+
+Read `SKILL.md` for a quick reference, or `AGENTS.md` for the full compiled guide.
+
+## File Structure
+
+```
+zod/
+├── SKILL.md          # Quick reference with rule index
+├── AGENTS.md         # Full compiled guide (all rules)
+├── metadata.json     # Version, categories, references
+├── README.md         # This file
+└── rules/
+    ├── _sections.md  # Category definitions
+    ├── _template.md  # Rule template
+    ├── schema-*.md   # Schema definition rules
+    ├── parse-*.md    # Parsing rules
+    ├── type-*.md     # Type inference rules
+    ├── error-*.md    # Error handling rules
+    ├── object-*.md   # Object schema rules
+    ├── compose-*.md  # Composition rules
+    ├── refine-*.md   # Refinement rules
+    └── perf-*.md     # Performance rules
+```
+
+## Rule Categories
+
+| Priority | Category | Rules | Impact |
+|----------|----------|-------|--------|
+| 1 | Schema Definition | 6 | CRITICAL |
+| 2 | Parsing & Validation | 6 | CRITICAL |
+| 3 | Type Inference | 5 | HIGH |
+| 4 | Error Handling | 5 | HIGH |
+| 5 | Object Schemas | 6 | MEDIUM-HIGH |
+| 6 | Schema Composition | 5 | MEDIUM |
+| 7 | Refinements & Transforms | 5 | MEDIUM |
+| 8 | Performance & Bundle | 5 | LOW-MEDIUM |
+
+## Key Principles
+
+1. **Type Safety First**: Always use `z.infer`, never duplicate types manually
+2. **Validate at Boundaries**: Parse external data immediately at entry points
+3. **User-Friendly Errors**: Provide custom messages, collect all issues
+4. **Single Source of Truth**: Schema defines validation AND TypeScript types
+5. **Composition Over Duplication**: Use extend, pick, omit, partial
+
+## References
+
+- [Zod Official Documentation](https://zod.dev/)
+- [Zod v4 Release Notes](https://zod.dev/v4)
+- [Zod GitHub](https://github.com/colinhacks/zod)
+- [Zod Mini](https://zod.dev/packages/mini)