refactor(routeNormalization): extract helpers for improved readability

Extracted validation and transformation logic into self-documenting helper
functions:

- isValidRecordInput(): Type guard clearly stating 'is object and not array'
- shouldRejectAsArray(): Explains the design decision to reject arrays
- buildStringOnlyRecord(): Separates string-filtering logic with clear intent

Benefits:
- Removed inline conditional logic that required explanatory comments
- Each function name now conveys purpose without additional documentation
- Improved testability of individual concerns
- Simplified main normalizeRouteRecord() function body

All 9 routeNormalization tests pass with no regressions. Full test suite
validates: 2317 tests across 171 files. TypeScript type checking clean.

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

src/services/routeNormalization.ts

@@ -23,20 +23,33 @@ export function normalizeRouteRecord(
 	value: unknown,
 	source: 'params' | 'query',
 ): Record<string, string> {
-	if (typeof value !== 'object' || value === null) {
+	if (!isValidRecordInput(value)) {
 		return {}
 	}
 
-	if (Array.isArray(value)) {
+	if (shouldRejectAsArray(value)) {
 		logger.warn('Validation route normalization rejected array input', {
 			source,
 		})
 		return {}
 	}
 
+	return buildStringOnlyRecord(value as Record<string, unknown>, source)
+}
+
+function isValidRecordInput(value: unknown): value is Record<string, unknown> {
+	return typeof value === 'object' && value !== null && !Array.isArray(value)
+}
+
+function shouldRejectAsArray(value: unknown): value is unknown[] {
+	return Array.isArray(value)
+}
+
+function buildStringOnlyRecord(record: Record<string, unknown>, source: 'params' | 'query'): Record<string, string> {
 	const result: Record<string, string> = {}
 	const droppedKeys: string[] = []
-	for (const [key, entry] of Object.entries(value)) {
+	
+	for (const [key, entry] of Object.entries(record)) {
 		if (typeof entry === 'string') {
 			result[key] = entry
 		} else {