feat: implement configuration management system

- Add comprehensive TypeScript interfaces for all config types
- Implement ConfigManager singleton class with layered loading
- Support for default, environment-specific, and environment variable configs
- Add example .env file for sensitive configuration

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

config/app.json

@@ -0,0 +1,19 @@
+{
+  "appName": "ERPAuto",
+  "version": "1.0.0",
+  "logLevel": "info",
+  "browser": {
+    "headless": false,
+    "slowMo": 50,
+    "timeout": 30000
+  },
+  "erp": {
+    "baseUrl": "https://68.11.34.30:8082",
+    "ignoreHttpsErrors": true
+  },
+  "paths": {
+    "tempDir": "./data/temp",
+    "outputDir": "./data/output",
+    "reportDir": "./data/reports"
+  }
+}