refactor: migrate hardcode detector from regex to AST-based analysis

- Replace regex-based matchers with tree-sitter AST traversal
- Add duplicate value tracking across files
- Implement boolean literal detection
- Add value type classification (email, url, ip, api_key, etc.)
- Improve context awareness with AST node analysis
- Reduce false positives with better constant detection

Breaking changes removed:
- BraceTracker.ts
- ExportConstantAnalyzer.ts
- MagicNumberMatcher.ts
- MagicStringMatcher.ts

New components added:
- AstTreeTraverser for AST walking
- DuplicateValueTracker for cross-file tracking
- AstContextChecker for node context analysis
- AstNumberAnalyzer, AstStringAnalyzer, AstBooleanAnalyzer
- ValuePatternMatcher for type detection

Test coverage: 87.97% statements, 96.75% functions

packages/guardian/src/infrastructure/analyzers/SecretDetector.ts

@@ -3,6 +3,7 @@ import type { SecretLintConfigDescriptor } from "@secretlint/types"
 import { ISecretDetector } from "../../domain/services/ISecretDetector"
 import { SecretViolation } from "../../domain/value-objects/SecretViolation"
 import { SECRET_KEYWORDS, SECRET_TYPE_NAMES } from "../../domain/constants/SecretExamples"
+import { EXTERNAL_PACKAGES } from "../../shared/constants/rules"
 
 /**
  * Detects hardcoded secrets in TypeScript/JavaScript code
@@ -25,7 +26,7 @@ export class SecretDetector implements ISecretDetector {
     private readonly secretlintConfig: SecretLintConfigDescriptor = {
         rules: [
             {
-                id: "@secretlint/secretlint-rule-preset-recommend",
+                id: EXTERNAL_PACKAGES.SECRETLINT_PRESET,
             },
         ],
     }