chore: refactor hardcoded values to constants (v0.5.1)

Major internal refactoring to eliminate hardcoded values and improve
maintainability. Guardian now fully passes its own quality checks!

Changes:
- Extract all RepositoryViolation messages to domain constants
- Extract all framework leak template strings to centralized constants
- Extract all layer paths to infrastructure constants
- Extract all regex patterns to IMPORT_PATTERNS constant
- Add 30+ new constants for better maintainability

New files:
- src/infrastructure/constants/paths.ts (layer paths, patterns)
- src/domain/constants/Messages.ts (25+ repository messages)
- src/domain/constants/FrameworkCategories.ts (framework categories)
- src/shared/constants/layers.ts (layer names)

Impact:
- Reduced hardcoded values from 37 to 1 (97% improvement)
- Guardian passes its own src/ directory checks with 0 violations
- All 292 tests still passing (100% pass rate)
- No breaking changes - fully backwards compatible

Test results:
- 292 tests passing (100% pass rate)
- 96.77% statement coverage
- 83.82% branch coverage

packages/guardian/src/infrastructure/constants/paths.ts

@@ -0,0 +1,17 @@
+export const LAYER_PATHS = {
+    DOMAIN: "/domain/",
+    APPLICATION: "/application/",
+    INFRASTRUCTURE: "/infrastructure/",
+    SHARED: "/shared/",
+} as const
+
+export const CLI_PATHS = {
+    DIST_CLI_INDEX: "../dist/cli/index.js",
+} as const
+
+export const IMPORT_PATTERNS = {
+    ES_IMPORT:
+        /import\s+(?:{[^}]*}|[\w*]+(?:\s+as\s+\w+)?|\*\s+as\s+\w+)\s+from\s+['"]([^'"]+)['"]/g,
+    REQUIRE: /require\s*\(\s*['"]([^'"]+)['"]\s*\)/g,
+    QUOTE: /['"]/g,
+} as const