chore(graft): 忽略本地图谱缓存并保持可检索

.gitignore

@@ -10,3 +10,6 @@ __pycache__/
 docs/superpowers
 server/api/*.sqlite*
 server/api/api
+
+# graft's local graph cache — regenerable, not committed (run `graft build`).
+/graft/

.ignore

@@ -0,0 +1,5 @@
+# graft's cards are gitignored but should stay greppable: ripgrep reads
+# .ignore before .gitignore, so this re-admits the tree to search only.
+!graft/
+graft/.cache/
+graft/.graph/