[main]: clean up

.gitignore

@@ -0,0 +1,21 @@
+# R session files
+.Rhistory
+.Rapp.history
+.RData
+.RDataTmp
+.Ruserdata
+
+# RStudio project/user state
+.Rproj.user/
+
+# renv local library/state (keep renv.lock and renv/activate.R tracked)
+renv/library/
+renv/python/
+renv/staging/
+
+# IDE/project metadata
+.idea/
+.vscode/
+
+# OS cruft
+.DS_Store