test: Phase 2 - Create test infrastructure

- Create comprehensive test directory structure
- Implement better-sqlite3 mock for Vitest
- Add node factory using fishery for test data generation
- Create workflow builder with fluent API
- Add infrastructure validation tests
- Update testing checklist to reflect progress

All Phase 2 tasks completed successfully with 7 tests passing.

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

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

tests/fixtures/factories/node.factory.ts

@@ -0,0 +1,121 @@
+import { Factory } from 'fishery';
+import { faker } from '@faker-js/faker';
+
+interface NodeDefinition {
+  name: string;
+  displayName: string;
+  description: string;
+  version: number;
+  defaults: { name: string };
+  inputs: string[];
+  outputs: string[];
+  properties: any[];
+  credentials?: any[];
+  group?: string[];
+}
+
+export const nodeFactory = Factory.define<NodeDefinition>(() => ({
+  name: faker.helpers.slugify(faker.word.noun()),
+  displayName: faker.company.name(),
+  description: faker.lorem.sentence(),
+  version: faker.number.int({ min: 1, max: 5 }),
+  defaults: {
+    name: faker.word.noun()
+  },
+  inputs: ['main'],
+  outputs: ['main'],
+  group: [faker.helpers.arrayElement(['transform', 'trigger', 'output'])],
+  properties: [
+    {
+      displayName: 'Resource',
+      name: 'resource',
+      type: 'options',
+      default: 'user',
+      options: [
+        { name: 'User', value: 'user' },
+        { name: 'Post', value: 'post' }
+      ]
+    }
+  ],
+  credentials: []
+}));
+
+// Specific node factories
+export const webhookNodeFactory = nodeFactory.params({
+  name: 'webhook',
+  displayName: 'Webhook',
+  description: 'Starts the workflow when a webhook is called',
+  group: ['trigger'],
+  properties: [
+    {
+      displayName: 'Path',
+      name: 'path',
+      type: 'string',
+      default: 'webhook',
+      required: true
+    },
+    {
+      displayName: 'Method',
+      name: 'method',
+      type: 'options',
+      default: 'GET',
+      options: [
+        { name: 'GET', value: 'GET' },
+        { name: 'POST', value: 'POST' }
+      ]
+    }
+  ]
+});
+
+export const slackNodeFactory = nodeFactory.params({
+  name: 'slack',
+  displayName: 'Slack',
+  description: 'Send messages to Slack',
+  group: ['output'],
+  credentials: [
+    {
+      name: 'slackApi',
+      required: true
+    }
+  ],
+  properties: [
+    {
+      displayName: 'Resource',
+      name: 'resource',
+      type: 'options',
+      default: 'message',
+      options: [
+        { name: 'Message', value: 'message' },
+        { name: 'Channel', value: 'channel' }
+      ]
+    },
+    {
+      displayName: 'Operation',
+      name: 'operation',
+      type: 'options',
+      displayOptions: {
+        show: {
+          resource: ['message']
+        }
+      },
+      default: 'post',
+      options: [
+        { name: 'Post', value: 'post' },
+        { name: 'Update', value: 'update' }
+      ]
+    },
+    {
+      displayName: 'Channel',
+      name: 'channel',
+      type: 'string',
+      required: true,
+      displayOptions: {
+        show: {
+          resource: ['message'],
+          operation: ['post']
+        }
+      },
+      default: ''
+    }
+  ]
+});