chore: Add .pnp.* files to .gitignore

Prevent Yarn PnP files from being accidentally committed.
The project uses node-modules linker (configured in .yarnrc.yml),
so .pnp.* files should not be generated or tracked.

Author: guyromellemagayano

.gitignore

@@ -39,3 +39,7 @@ yarn-error.log*
 # Firebase
 .firebase
 firebase-debug.log
+
+# Yarn PnP (not used - we use node-modules linker)
+.pnp.*
+.pnp