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/src/api.ts

@@ -9,12 +9,14 @@ import { IHardcodeDetector } from "./domain/services/IHardcodeDetector"
 import { INamingConventionDetector } from "./domain/services/INamingConventionDetector"
 import { IFrameworkLeakDetector } from "./domain/services/IFrameworkLeakDetector"
 import { IEntityExposureDetector } from "./domain/services/IEntityExposureDetector"
+import { IDependencyDirectionDetector } from "./domain/services/IDependencyDirectionDetector"
 import { FileScanner } from "./infrastructure/scanners/FileScanner"
 import { CodeParser } from "./infrastructure/parsers/CodeParser"
 import { HardcodeDetector } from "./infrastructure/analyzers/HardcodeDetector"
 import { NamingConventionDetector } from "./infrastructure/analyzers/NamingConventionDetector"
 import { FrameworkLeakDetector } from "./infrastructure/analyzers/FrameworkLeakDetector"
 import { EntityExposureDetector } from "./infrastructure/analyzers/EntityExposureDetector"
+import { DependencyDirectionDetector } from "./infrastructure/analyzers/DependencyDirectionDetector"
 import { ERROR_MESSAGES } from "./shared/constants"
 
 /**
@@ -69,6 +71,8 @@ export async function analyzeProject(
     const namingConventionDetector: INamingConventionDetector = new NamingConventionDetector()
     const frameworkLeakDetector: IFrameworkLeakDetector = new FrameworkLeakDetector()
     const entityExposureDetector: IEntityExposureDetector = new EntityExposureDetector()
+    const dependencyDirectionDetector: IDependencyDirectionDetector =
+        new DependencyDirectionDetector()
     const useCase = new AnalyzeProject(
         fileScanner,
         codeParser,
@@ -76,6 +80,7 @@ export async function analyzeProject(
         namingConventionDetector,
         frameworkLeakDetector,
         entityExposureDetector,
+        dependencyDirectionDetector,
     )
 
     const result = await useCase.execute(options)
@@ -96,5 +101,6 @@ export type {
     NamingConventionViolation,
     FrameworkLeakViolation,
     EntityExposureViolation,
+    DependencyDirectionViolation,
     ProjectMetrics,
 } from "./application/use-cases/AnalyzeProject"