refactor: extract detector logic into focused strategy classes

Refactored three largest detectors to improve maintainability and reduce complexity:

- AggregateBoundaryDetector: 381 → 162 lines (57% reduction)
- HardcodeDetector: 459 → 89 lines (81% reduction)
- RepositoryPatternDetector: 479 → 106 lines (78% reduction)

Added 13 new strategy classes:
- FolderRegistry - centralized DDD folder name management
- AggregatePathAnalyzer - path parsing and aggregate extraction
- ImportValidator - import validation logic
- BraceTracker - brace and bracket counting
- ConstantsFileChecker - constants file detection
- ExportConstantAnalyzer - export const analysis
- MagicNumberMatcher - magic number detection
- MagicStringMatcher - magic string detection
- OrmTypeMatcher - ORM type matching
- MethodNameValidator - repository method validation
- RepositoryFileAnalyzer - file role detection
- RepositoryViolationDetector - violation detection logic

All 519 tests passing, zero ESLint errors, no breaking changes.

packages/guardian/src/infrastructure/strategies/ImportValidator.ts

@@ -0,0 +1,150 @@
+import { IMPORT_PATTERNS } from "../constants/paths"
+import { AggregatePathAnalyzer } from "./AggregatePathAnalyzer"
+import { FolderRegistry } from "./FolderRegistry"
+
+/**
+ * Validates imports for aggregate boundary violations
+ *
+ * Checks if imports cross aggregate boundaries inappropriately
+ * and ensures proper encapsulation in DDD architecture.
+ */
+export class ImportValidator {
+    constructor(
+        private readonly folderRegistry: FolderRegistry,
+        private readonly pathAnalyzer: AggregatePathAnalyzer,
+    ) {}
+
+    /**
+     * Checks if an import violates aggregate boundaries
+     */
+    public isViolation(importPath: string, currentAggregate: string): boolean {
+        const normalizedPath = this.normalizeImportPath(importPath)
+
+        if (!this.isValidImportPath(normalizedPath)) {
+            return false
+        }
+
+        if (this.isInternalBoundedContextImport(normalizedPath)) {
+            return false
+        }
+
+        const targetAggregate = this.pathAnalyzer.extractAggregateFromImport(normalizedPath)
+        if (!targetAggregate || targetAggregate === currentAggregate) {
+            return false
+        }
+
+        if (this.isAllowedImport(normalizedPath)) {
+            return false
+        }
+
+        return this.seemsLikeEntityImport(normalizedPath)
+    }
+
+    /**
+     * Extracts all import paths from a line of code
+     */
+    public extractImports(line: string): string[] {
+        const imports: string[] = []
+
+        this.extractEsImports(line, imports)
+        this.extractRequireImports(line, imports)
+
+        return imports
+    }
+
+    /**
+     * Normalizes an import path for consistent processing
+     */
+    private normalizeImportPath(importPath: string): string {
+        return importPath.replace(IMPORT_PATTERNS.QUOTE, "").toLowerCase()
+    }
+
+    /**
+     * Checks if import path is valid for analysis
+     */
+    private isValidImportPath(normalizedPath: string): boolean {
+        if (!normalizedPath.includes("/")) {
+            return false
+        }
+
+        if (!normalizedPath.startsWith(".") && !normalizedPath.startsWith("/")) {
+            return false
+        }
+
+        return true
+    }
+
+    /**
+     * Checks if import is internal to the same bounded context
+     */
+    private isInternalBoundedContextImport(normalizedPath: string): boolean {
+        const parts = normalizedPath.split("/")
+        const dotDotCount = parts.filter((p) => p === "..").length
+
+        if (dotDotCount === 1) {
+            const nonDotParts = parts.filter((p) => p !== ".." && p !== ".")
+            if (nonDotParts.length >= 1) {
+                const firstFolder = nonDotParts[0]
+                if (this.folderRegistry.isEntityFolder(firstFolder)) {
+                    return true
+                }
+            }
+        }
+
+        return false
+    }
+
+    /**
+     * Checks if import is from an allowed folder
+     */
+    private isAllowedImport(normalizedPath: string): boolean {
+        for (const folderName of this.folderRegistry.allowedFolders) {
+            if (normalizedPath.includes(`/${folderName}/`)) {
+                return true
+            }
+        }
+        return false
+    }
+
+    /**
+     * Checks if import seems to be an entity
+     */
+    private seemsLikeEntityImport(normalizedPath: string): boolean {
+        const pathParts = normalizedPath.split("/")
+        const lastPart = pathParts[pathParts.length - 1]
+
+        if (!lastPart) {
+            return false
+        }
+
+        const filename = lastPart.replace(/\.(ts|js)$/, "")
+
+        if (filename.length > 0 && /^[a-z][a-z]/.exec(filename)) {
+            return true
+        }
+
+        return false
+    }
+
+    /**
+     * Extracts ES6 imports from a line
+     */
+    private extractEsImports(line: string, imports: string[]): void {
+        let match = IMPORT_PATTERNS.ES_IMPORT.exec(line)
+        while (match) {
+            imports.push(match[1])
+            match = IMPORT_PATTERNS.ES_IMPORT.exec(line)
+        }
+    }
+
+    /**
+     * Extracts CommonJS requires from a line
+     */
+    private extractRequireImports(line: string, imports: string[]): void {
+        let match = IMPORT_PATTERNS.REQUIRE.exec(line)
+        while (match) {
+            imports.push(match[1])
+            match = IMPORT_PATTERNS.REQUIRE.exec(line)
+        }
+    }
+}