ci: incremental backend tests, cached web dependencies, web build in parallel with the tests

.woodpecker/verify.yml

@@ -23,4 +23,5 @@ steps:
     environment:
       NUGET_PACKAGES: /home/justme/.nuget/packages
     commands:
-      - cd backend && dotnet test --solution MoShiro.slnx -c Release
+      # 增量编译 + 测试（把后端源码同步到固定目录，只重编译变了的项目），见 ci/verify-backend.sh
+      - bash ci/verify-backend.sh