diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..3dbe094
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,4 @@
+# Workbooks are binary to git, but render readable diffs through textconv
+*.xlsx  diff=xlsx
+*.xlsm  diff=xlsx
+*.xlsb  diff=xlsx
diff --git a/.gitignore b/.gitignore
index 705f828..0c96895 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,4 +5,28 @@ Exported_files/
 *.png
 ~$*
 *.tmp
-*.temp
\ No newline at end of file
+*.temp
+# ---- run/ : allowlist. Ignore all, then re-include text case artifacts. ----
+# (run/ does not exist yet — these rules take effect the moment VEDA creates it)
+run/**
+!run/**/
+!run/**/*.run
+!run/**/*.cmd
+!run/**/*.bat
+!run/**/*.opt
+
+run/**/*.gdx
+run/**/*.dd
+run/GAMSSAVE/**
+
+# ---- Excel and VEDA transient files ----
+~$*.xlsx
+~$*.xlsb
+*.xlk
+AppData/
+GAMS_WrkTIMES/
+
+# ---- Logs and scratch ----
+*.lst
+*.log
+sandbox/
diff --git a/CLAIMS.md b/CLAIMS.md
new file mode 100644
index 0000000..3186401
--- /dev/null
+++ b/CLAIMS.md
@@ -0,0 +1,7 @@
+# Active claims
+
+Claim a workbook before editing it. Release it immediately after merging.
+If your expected release date passes, update this file rather than letting it go stale.
+
+| File | Who | Since | Expected release |
+|---|---|---|---|