[CLAUDE] Cleanup: untrack orphan .claude.zip + docs.zip + ignore *.zip

Lỡ tay add -A vào commit `2a53107` cuốn 2 file zip rác từ Claude harness
(orphan dump session start). Untrack + add .gitignore rule *.zip để
không tái phạm.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -77,3 +77,6 @@ src/Backend/SolutionErp.Api/wwwroot/exports/
 # .claude/  ← DO NOT ignore, skills are committed
 !.claude/
 !.claude/**
+
+# Claude harness orphan dumps
+*.zip