chore: ignore CLAUDE.md (keep local only)

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: antoine-gourgue

.gitignore

@@ -7,4 +7,7 @@ api/.env
 web/.env
 web/goupixdex.key
 web/goupixdex.key.pub
-integrations
+integrations
+
+# Local Cursor / agent guidelines — not versioned
+CLAUDE.md