refactor: hardcode erp headless and browser settings instead of env vars

- Removed ERP_HEADLESS, ERP_IGNORE_HTTPS_ERRORS, ERP_AUTO_CLOSE_BROWSER from ConfigManager .env operations.
- Hardcoded these values in ConfigManager's default settings and getAllSettings() return.
- Hardcoded ignoreHTTPSErrors to true inside ErpBrowserManager when creating a new browser context.

Co-authored-by: luwamgere15-crypto <255338376+luwamgere15-crypto@users.noreply.github.com>

src/main/services/erp/ErpBrowserManager.ts

@@ -90,7 +90,7 @@ export class ErpBrowserManager {
     const context = await browserInstance.newContext({
       acceptDownloads: this.config.acceptDownloads,
       viewport: this.config.viewport,
-      ignoreHTTPSErrors: this.config.ignoreHTTPSErrors,
+      ignoreHTTPSErrors: true,
       javaScriptEnabled: true
     })