feat: add dependency direction enforcement (v0.4.0)

Implement dependency direction detection to enforce Clean Architecture rules:
- Domain layer can only import from Domain and Shared
- Application layer can only import from Domain, Application, and Shared
- Infrastructure layer can import from all layers
- Shared layer can be imported by all layers

Added:
- IDependencyDirectionDetector interface in domain layer
- DependencyViolation value object with detailed suggestions and examples
- DependencyDirectionDetector implementation in infrastructure
- Integration with AnalyzeProject use case
- New DEPENDENCY_DIRECTION rule in constants
- 43 comprehensive tests covering all scenarios (100% passing)
- Good and bad examples in examples directory

Improvements:
- Optimized extractLayerFromImport method to reduce complexity
- Fixed indentation in DependencyGraph.ts
- Updated getExampleFix to avoid false positives in old detector

Test Results:
- All 261 tests passing
- Build successful
- Self-check: 0 architecture violations in src code

packages/guardian/examples/good-architecture/dependency-direction/GoodDomainLayer.ts

@@ -0,0 +1,56 @@
+/**
+ * ✅ GOOD: Domain layer with correct dependencies
+ *
+ * Domain should only import from:
+ * - Other domain files
+ * - Shared utilities
+ *
+ * Domain should NOT import from:
+ * - Application layer
+ * - Infrastructure layer
+ */
+
+import { Email } from "../domain/value-objects/Email"
+import { UserId } from "../domain/value-objects/UserId"
+import { Result } from "../../../src/shared/types/Result"
+
+/**
+ * ✅ Domain entity using only domain value objects and shared types
+ */
+export class User {
+    private readonly id: UserId
+    private email: Email
+    private readonly createdAt: Date
+
+    constructor(id: UserId, email: Email, createdAt: Date = new Date()) {
+        this.id = id
+        this.email = email
+        this.createdAt = createdAt
+    }
+
+    public getId(): UserId {
+        return this.id
+    }
+
+    public getEmail(): Email {
+        return this.email
+    }
+
+    public changeEmail(newEmail: Email): Result<void> {
+        if (this.email.equals(newEmail)) {
+            return Result.fail("Email is the same")
+        }
+
+        this.email = newEmail
+        return Result.ok()
+    }
+}
+
+/**
+ * ✅ Domain repository interface (not importing from infrastructure)
+ */
+export interface IUserRepository {
+    findById(id: UserId): Promise<User | null>
+    save(user: User): Promise<void>
+    delete(id: UserId): Promise<void>
+}