feat: add aggregate boundary validation (v0.7.0)

Implement DDD aggregate boundary validation to detect and prevent direct
entity references across aggregate boundaries.

Features:
- Detect direct entity imports between aggregates
- Allow only ID or Value Object references
- Support multiple folder structures (domain/aggregates/*, domain/*, domain/entities/*)
- Filter allowed imports (value-objects, events, repositories, services)
- Critical severity level for violations
- 41 comprehensive tests with 92.55% coverage
- CLI output with detailed suggestions
- Examples of good and bad patterns

Breaking changes: None
Backwards compatible: Yes

packages/guardian/src/api.ts

@@ -11,6 +11,7 @@ import { IFrameworkLeakDetector } from "./domain/services/IFrameworkLeakDetector
 import { IEntityExposureDetector } from "./domain/services/IEntityExposureDetector"
 import { IDependencyDirectionDetector } from "./domain/services/IDependencyDirectionDetector"
 import { IRepositoryPatternDetector } from "./domain/services/RepositoryPatternDetectorService"
+import { IAggregateBoundaryDetector } from "./domain/services/IAggregateBoundaryDetector"
 import { FileScanner } from "./infrastructure/scanners/FileScanner"
 import { CodeParser } from "./infrastructure/parsers/CodeParser"
 import { HardcodeDetector } from "./infrastructure/analyzers/HardcodeDetector"
@@ -19,6 +20,7 @@ import { FrameworkLeakDetector } from "./infrastructure/analyzers/FrameworkLeakD
 import { EntityExposureDetector } from "./infrastructure/analyzers/EntityExposureDetector"
 import { DependencyDirectionDetector } from "./infrastructure/analyzers/DependencyDirectionDetector"
 import { RepositoryPatternDetector } from "./infrastructure/analyzers/RepositoryPatternDetector"
+import { AggregateBoundaryDetector } from "./infrastructure/analyzers/AggregateBoundaryDetector"
 import { ERROR_MESSAGES } from "./shared/constants"
 
 /**
@@ -76,6 +78,7 @@ export async function analyzeProject(
     const dependencyDirectionDetector: IDependencyDirectionDetector =
         new DependencyDirectionDetector()
     const repositoryPatternDetector: IRepositoryPatternDetector = new RepositoryPatternDetector()
+    const aggregateBoundaryDetector: IAggregateBoundaryDetector = new AggregateBoundaryDetector()
     const useCase = new AnalyzeProject(
         fileScanner,
         codeParser,
@@ -85,6 +88,7 @@ export async function analyzeProject(
         entityExposureDetector,
         dependencyDirectionDetector,
         repositoryPatternDetector,
+        aggregateBoundaryDetector,
     )
 
     const result = await useCase.execute(options)
@@ -107,5 +111,6 @@ export type {
     EntityExposureViolation,
     DependencyDirectionViolation,
     RepositoryPatternViolation,
+    AggregateBoundaryViolation,
     ProjectMetrics,
 } from "./application/use-cases/AnalyzeProject"