feat: implement dotenv secrets loading from /home/admin/secrets/.env

- Added dotenv package to load environment variables from absolute path
- Secrets now loaded automatically on app startup, no manual sourcing needed
- Secrets file secured with chmod 600, outside project directory
- Enables persistent secrets across service restarts
- Tested: Job submission flow working end-to-end with all steps completing

extracted-graph-logic/config.js

@@ -0,0 +1,14 @@
+// SharePoint/OneDrive Configuration
+// These IDs specify where folders and files will be created
+
+const DRIVE_ID = "b!9YOqqr2xM0G2DFBwMEJYY4UzQgocFddEtpLYWuS9_AtkCKl2q8yjQJteQ7Ti4QSx";
+const PARENT_ITEM_ID = "01SPNXLDW3Y56HAWK5CNAJ4YJLLSQCUCJ7";
+
+// Azure AD App Configuration
+const CLIENT_ID = "3c846e71-9609-40e1-b458-0eb805e21b9f";
+
+module.exports = {
+  DRIVE_ID,
+  PARENT_ITEM_ID,
+  CLIENT_ID
+};