chore: configure auto-push to remote on every commit

- Enable git push.autoSetupRemote for automatic tracking setup
- Add push.followTags to include tags in pushes
- Install post-commit hook for automatic push after each commit
- Update config.json to document auto-push behavior
- Remote: master (giteas.fullmooncyberworks.com/mystiatech/Mai)

All commits will now automatically push to the remote branch.

.planning/config.json

@@ -8,5 +8,10 @@
     "research": true,
     "plan_check": true,
     "verifier": true
+  },
+  "git": {
+    "auto_push": true,
+    "push_tags": true,
+    "remote": "master"
   }
 }