Remove tracked local tooling artifacts.

Stop tracking remaining `.cursor` and `.DS_Store` files and ignore future local-only editor metadata so the public repo only keeps source and CI assets.

Author: Kenbak

.DS_Store

@@ -8,6 +8,7 @@
 .bizdev-outreach.md
 .cursor/
 .cargo-home/
+.DS_Store
 
 # Internal docs (referral program, strategy)
 docs/REFERRAL-*