test: implement comprehensive testing improvements from PR #104 review

Major improvements based on comprehensive test suite review:

Test Fixes:
- Fix all 78 failing tests across logger, MSW, and validator tests
- Fix console spy management in logger tests with proper DEBUG env handling
- Fix MSW test environment restoration in session-management.test.ts
- Fix workflow validator tests by adding proper node connections
- Fix mock setup issues in edge case tests

Test Organization:
- Split large config-validator.test.ts (1,075 lines) into 4 focused files
- Rename 63+ tests to follow "should X when Y" naming convention
- Add comprehensive edge case test files for all major validators
- Create tests/README.md with testing guidelines and best practices

New Features:
- Add ConfigValidator.validateBatch() method for bulk validation
- Add edge case coverage for null/undefined, boundaries, invalid data
- Add CI-aware performance test timeouts
- Add JSDoc comments to test utilities and factories
- Add workflow duplicate node name validation tests

Results:
- All tests passing: 1,356 passed, 19 skipped
- Test coverage: 85.34% statements, 85.3% branches
- From 78 failures to 0 failures

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/factories/property-definition-factory.ts

@@ -1,6 +1,10 @@
 import { Factory } from 'fishery';
 import { faker } from '@faker-js/faker';
 
+/**
+ * Interface for n8n node property definitions.
+ * Represents the structure of properties that configure node behavior.
+ */
 interface PropertyDefinition {
   name: string;
   displayName: string;
@@ -11,6 +15,37 @@ interface PropertyDefinition {
   options?: any[];
 }
 
+/**
+ * Factory for generating PropertyDefinition test data.
+ * Creates realistic property configurations for testing node validation and processing.
+ * 
+ * @example
+ * ```typescript
+ * // Create a single property
+ * const prop = PropertyDefinitionFactory.build();
+ * 
+ * // Create a required string property
+ * const urlProp = PropertyDefinitionFactory.build({
+ *   name: 'url',
+ *   displayName: 'URL',
+ *   type: 'string',
+ *   required: true
+ * });
+ * 
+ * // Create an options property with choices
+ * const methodProp = PropertyDefinitionFactory.build({
+ *   name: 'method',
+ *   type: 'options',
+ *   options: [
+ *     { name: 'GET', value: 'GET' },
+ *     { name: 'POST', value: 'POST' }
+ *   ]
+ * });
+ * 
+ * // Create multiple properties for a node
+ * const nodeProperties = PropertyDefinitionFactory.buildList(5);
+ * ```
+ */
 export const PropertyDefinitionFactory = Factory.define<PropertyDefinition>(() => ({
   name: faker.word.noun() + faker.word.adjective().charAt(0).toUpperCase() + faker.word.adjective().slice(1),
   displayName: faker.helpers.arrayElement(['URL', 'Method', 'Headers', 'Body', 'Authentication']),