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/ConstantsFileChecker.ts

@@ -0,0 +1,21 @@
+/**
+ * Checks if a file is a constants definition file
+ *
+ * Identifies files that should be skipped for hardcode detection
+ * since they are meant to contain constant definitions.
+ */
+export class ConstantsFileChecker {
+    private readonly constantsPatterns = [
+        /^constants?\.(ts|js)$/i,
+        /constants?\/.*\.(ts|js)$/i,
+        /\/(constants|config|settings|defaults|tokens)\.ts$/i,
+        /\/di\/tokens\.(ts|js)$/i,
+    ]
+
+    /**
+     * Checks if a file path represents a constants file
+     */
+    public isConstantsFile(filePath: string): boolean {
+        return this.constantsPatterns.some((pattern) => pattern.test(filePath))
+    }
+}