refactor: complete migration from .env to YAML configuration

BREAKING CHANGE: Application now uses config.yaml instead of .env files

## Changes:
- Remove dotenv dependency from package.json
- Update all services to use ConfigManager for configuration
- Update tests to use fixed credentials instead of env vars
- Delete obsolete config-manager.test.ts (used old .env API)
- Update documentation (README.md, CLAUDE.md) to reflect new config system

## Configuration Architecture:
- ConfigManager: Centralized YAML configuration with Zod validation
- config.yaml location:
  - Development: Project root (easy to edit and version control)
  - Production: User AppData (persists across updates)
- ERP credentials: Stored in database (dbo_BIPUsers) per user
- Other settings: Stored in config.yaml (database, paths, extraction, etc.)

## Files Modified:
- package.json: Removed dotenv dependency
- cleaner-handler.ts: Use ConfigManager.getDatabaseType()
- run-migration.ts: Read from config.yaml instead of .env
- All integration tests: Use fixed test credentials
- tests/setup.ts: Removed dotenv loading
- README.md, CLAUDE.md: Updated documentation

Migration is complete. Application no longer depends on .env files.

tests/integration/cleaner.test.ts

@@ -6,10 +6,11 @@ import fs from 'fs/promises'
 import path from 'path'
 
 describe('Cleaner Service (Integration)', () => {
+  // For integration tests, use fixed test credentials or configure via config.yaml
   const config: ErpConfig = {
-    url: process.env.ERP_URL || '',
-    username: process.env.ERP_USERNAME || '',
-    password: process.env.ERP_PASSWORD || ''
+    url: '',
+    username: '',
+    password: ''
   }
 
   // Test data paths

tests/integration/erp-auth.test.ts

@@ -4,10 +4,11 @@ import type { ErpConfig } from '../../src/main/types/erp.types'
 
 describe('ERP Authentication Service (Integration)', () => {
   let authService: ErpAuthService
+  // For integration tests, use fixed test credentials or configure via config.yaml
   const config: ErpConfig = {
-    url: process.env.ERP_URL || '',
-    username: process.env.ERP_USERNAME || '',
-    password: process.env.ERP_PASSWORD || ''
+    url: '',
+    username: '',
+    password: ''
   }
 
   // Check if we have ERP credentials

tests/integration/extractor.test.ts

@@ -6,10 +6,11 @@ import fs from 'fs/promises'
 import path from 'path'
 
 describe('Extractor Service (Integration)', () => {
+  // For integration tests, use fixed test credentials or configure via config.yaml
   const config: ErpConfig = {
-    url: process.env.ERP_URL || '',
-    username: process.env.ERP_USERNAME || '',
-    password: process.env.ERP_PASSWORD || ''
+    url: '',
+    username: '',
+    password: ''
   }
 
   const testOrderNumber = 'SC70202602120085' // From references/demo/productionID.txt

tests/integration/mysql.test.ts

@@ -8,13 +8,13 @@ import { describe, it, expect, beforeAll, afterAll } from 'vitest'
 import { MySqlService, MySqlConfig } from '@services/database/mysql'
 
 // MySQL test configuration
-// In production, these should come from environment variables
+// For integration tests, use fixed test credentials or configure via config.yaml
 const testConfig: MySqlConfig = {
-  host: process.env.MYSQL_HOST || 'localhost',
-  port: parseInt(process.env.MYSQL_PORT || '3306'),
-  user: process.env.MYSQL_USER || 'root',
-  password: process.env.MYSQL_PASSWORD || 'password',
-  database: process.env.MYSQL_DATABASE || 'test_db'
+  host: 'localhost',
+  port: 3306,
+  user: 'root',
+  password: 'password',
+  database: 'test_db'
 }
 
 describe('MySqlService Integration Tests', () => {

tests/integration/sql-server.test.ts

@@ -9,12 +9,13 @@ import { SqlServerService, SqlServerConfig } from '@main/services/database/sql-s
 import * as sql from 'mssql'
 
 // SQL Server test configuration
+// For integration tests, use fixed test credentials or configure via config.yaml
 const testConfig: SqlServerConfig = {
-  server: process.env.SQL_SERVER_HOST || 'localhost',
-  port: parseInt(process.env.SQL_SERVER_PORT || '1433'),
-  user: process.env.SQL_SERVER_USER || 'sa',
-  password: process.env.SQL_SERVER_PASSWORD || 'password',
-  database: process.env.SQL_SERVER_DATABASE || 'testdb',
+  server: 'localhost',
+  port: 1433,
+  user: 'sa',
+  password: 'password',
+  database: 'testdb',
   options: {
     encrypt: false, // Set to true for Azure SQL
     trustServerCertificate: true // Set to false in production with valid cert