feat: add repository pattern validation (v0.5.0)

Add comprehensive Repository Pattern validation to detect violations
and ensure proper domain-infrastructure separation.

Features:
- ORM type detection in repository interfaces (25+ patterns)
- Concrete repository usage detection in use cases
- Repository instantiation detection (new Repository())
- Domain language validation for repository methods
- Smart violation reporting with fix suggestions

Tests:
- 31 new tests for repository pattern detection
- 292 total tests passing (100% pass rate)
- 96.77% statement coverage, 83.82% branch coverage

Examples:
- 8 example files (4 bad patterns, 4 good patterns)
- Demonstrates Clean Architecture and SOLID principles

packages/guardian/examples/repository-pattern/README.md

@@ -0,0 +1,220 @@
+# Repository Pattern Examples
+
+This directory contains examples demonstrating proper and improper implementations of the Repository Pattern.
+
+## Overview
+
+The Repository Pattern provides an abstraction layer between domain logic and data access. A well-implemented repository:
+
+1. Uses domain types, not ORM-specific types
+2. Depends on interfaces, not concrete implementations
+3. Uses dependency injection, not direct instantiation
+4. Uses domain language, not technical database terms
+
+## Examples
+
+### ❌ Bad Examples
+
+#### 1. ORM Types in Interface
+**File:** `bad-orm-types-in-interface.ts`
+
+**Problem:** Repository interface exposes Prisma-specific types (`Prisma.UserWhereInput`, `Prisma.UserCreateInput`). This couples the domain layer to infrastructure concerns.
+
+**Violations:**
+- Domain depends on ORM library
+- Cannot swap ORM without changing domain
+- Breaks Clean Architecture principles
+
+#### 2. Concrete Repository in Use Case
+**File:** `bad-concrete-repository-in-use-case.ts`
+
+**Problem:** Use case depends on `PrismaUserRepository` instead of `IUserRepository` interface.
+
+**Violations:**
+- Violates Dependency Inversion Principle
+- Cannot easily mock for testing
+- Tightly coupled to specific implementation
+
+#### 3. Creating Repository with 'new'
+**File:** `bad-new-repository.ts`
+
+**Problem:** Use case instantiates repositories with `new UserRepository()` instead of receiving them through constructor.
+
+**Violations:**
+- Violates Dependency Injection principle
+- Hard to test (cannot mock dependencies)
+- Hidden dependencies
+- Creates tight coupling
+
+#### 4. Technical Method Names
+**File:** `bad-technical-method-names.ts`
+
+**Problem:** Repository methods use database/SQL terminology (`findOne`, `insert`, `query`, `execute`).
+
+**Violations:**
+- Uses technical terms instead of domain language
+- Exposes implementation details
+- Not aligned with ubiquitous language
+
+### ✅ Good Examples
+
+#### 1. Clean Interface
+**File:** `good-clean-interface.ts`
+
+**Benefits:**
+- Uses only domain types (UserId, Email, User)
+- ORM-agnostic interface
+- Easy to understand and maintain
+- Follows Clean Architecture
+
+```typescript
+interface IUserRepository {
+    findById(id: UserId): Promise<User | null>
+    findByEmail(email: Email): Promise<User | null>
+    save(user: User): Promise<void>
+    delete(id: UserId): Promise<void>
+}
+```
+
+#### 2. Interface in Use Case
+**File:** `good-interface-in-use-case.ts`
+
+**Benefits:**
+- Depends on interface, not concrete class
+- Easy to test with mocks
+- Can swap implementations
+- Follows Dependency Inversion Principle
+
+```typescript
+class CreateUser {
+    constructor(private readonly userRepo: IUserRepository) {}
+
+    async execute(data: CreateUserRequest): Promise<UserResponseDto> {
+        // Uses interface, not concrete implementation
+    }
+}
+```
+
+#### 3. Dependency Injection
+**File:** `good-dependency-injection.ts`
+
+**Benefits:**
+- All dependencies injected through constructor
+- Explicit dependencies (no hidden coupling)
+- Easy to test with mocks
+- Follows SOLID principles
+
+```typescript
+class CreateUser {
+    constructor(
+        private readonly userRepo: IUserRepository,
+        private readonly emailService: IEmailService
+    ) {}
+}
+```
+
+#### 4. Domain Language
+**File:** `good-domain-language.ts`
+
+**Benefits:**
+- Methods use business-oriented names
+- Self-documenting interface
+- Aligns with ubiquitous language
+- Hides implementation details
+
+```typescript
+interface IUserRepository {
+    findById(id: UserId): Promise<User | null>
+    findByEmail(email: Email): Promise<User | null>
+    findActiveUsers(): Promise<User[]>
+    save(user: User): Promise<void>
+    search(criteria: UserSearchCriteria): Promise<User[]>
+}
+```
+
+## Key Principles
+
+### 1. Persistence Ignorance
+Domain entities and repositories should not know about how data is persisted.
+
+```typescript
+// ❌ Bad: Domain knows about Prisma
+interface IUserRepository {
+    find(query: Prisma.UserWhereInput): Promise<User>
+}
+
+// ✅ Good: Domain uses own types
+interface IUserRepository {
+    findById(id: UserId): Promise<User | null>
+}
+```
+
+### 2. Dependency Inversion
+High-level modules (use cases) should not depend on low-level modules (repositories). Both should depend on abstractions (interfaces).
+
+```typescript
+// ❌ Bad: Use case depends on concrete repository
+class CreateUser {
+    constructor(private repo: PrismaUserRepository) {}
+}
+
+// ✅ Good: Use case depends on interface
+class CreateUser {
+    constructor(private repo: IUserRepository) {}
+}
+```
+
+### 3. Dependency Injection
+Don't create dependencies inside classes. Inject them through constructor.
+
+```typescript
+// ❌ Bad: Creates dependency
+class CreateUser {
+    execute() {
+        const repo = new UserRepository()
+    }
+}
+
+// ✅ Good: Injects dependency
+class CreateUser {
+    constructor(private readonly repo: IUserRepository) {}
+}
+```
+
+### 4. Ubiquitous Language
+Use domain language everywhere, including repository methods.
+
+```typescript
+// ❌ Bad: Technical terminology
+interface IUserRepository {
+    findOne(id: string): Promise<User>
+    insert(user: User): Promise<void>
+}
+
+// ✅ Good: Domain language
+interface IUserRepository {
+    findById(id: UserId): Promise<User | null>
+    save(user: User): Promise<void>
+}
+```
+
+## Testing with Guardian
+
+Run Guardian to detect Repository Pattern violations:
+
+```bash
+guardian check --root ./examples/repository-pattern
+```
+
+Guardian will detect:
+- ORM types in repository interfaces
+- Concrete repository usage in use cases
+- Repository instantiation with 'new'
+- Technical method names in repositories
+
+## Further Reading
+
+- [Clean Architecture by Robert C. Martin](https://blog.cleancoder.com/uncle-bob/2012/08/13/the-clean-architecture.html)
+- [Domain-Driven Design by Eric Evans](https://www.domainlanguage.com/ddd/)
+- [Repository Pattern - Martin Fowler](https://martinfowler.com/eaaCatalog/repository.html)
+- [SOLID Principles](https://en.wikipedia.org/wiki/SOLID)