fix: use glob pattern in .gitignore to track sample lib/ folders
The lib/ negation rules had incorrect webapp folder names
(appreactsampleb2e/appreactsampleb2x instead of
propertymanagementapp/propertyrentalapp), causing the sample lib/
directories to remain git-ignored. Replaced with a simpler
!samples/**/lib/ glob that is resilient to future name changes.
Made-with: Cursor