chore: gitignore .claude directory (#7121)

Because we don't have any team-wide skills in this directory and it is
easy to accidentally include .claude worktrees, settings, or skills in
here that shouldn't be committed to version control (at least for now)
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Author: rootulp

.gitignore

@@ -37,4 +37,4 @@ tools/talis/talis
 .cache
 .gomodcache
 # Claude Code local settings
-.claude/*.local.json
+.claude/*