fix: 添加.gitignore规则排除编译产物 + 添加10轮持续调试报告

- 排除 voice-service/main, main2, voice-svc-new (各8.5MB)
- 排除 gateway/cmd/gateway (15MB)
- 添加 docs/fixes/2026-05-19-round7-continuous-debugging-report.md
  10轮持续调试汇总: 19个Bug (5 P0, 5 P1, 4 P2, 5 P3)

.gitignore

@@ -36,6 +36,14 @@ backend/tool-engine/tool-engine
 backend/voice-service/voice-service
 backend/voice-service/cmd/voice-service
 
+# Compiled binaries (voice-service)
+backend/voice-service/main
+backend/voice-service/main2
+backend/voice-service/voice-svc-new
+
+# Compiled binaries (gateway)
+backend/gateway/cmd/gateway
+
 # Stale build artifact (legacy)
 backend/cmd