test running / reporting improvements (#797)

**CI/CD improvements (validate.yml):**
- Add test reporter (`ue-foundation/test-reporter@v2`) for all three platforms, rendering JUnit test results directly in PR check runs
- Add "Trust workspace" step on Windows to fix git safe.directory ownership issue with self-hosted runners
- Clean stale report files before each test run to prevent false failures from leftover XML
- Broaden `paths-ignore` to skip builds for non-code changes (`*.md`, `LICENSE`, `.gitignore`, `docs/**`)

**Test improvements:**
- Convert `CHECK` to `REQUIRE` in several test suites (projectstore, integration, http) for fail-fast behavior
- Mark some tests with `doctest::skip()` for selective execution
- Skip httpclient transport tests pending investigation
- Add `--noskip` option to `xmake test` task
- Add `--repeat=<N>` option to `xmake test` task, to run tests repeatedly N times or until there is a failure

**xmake test output improvements:**
- Add totals row to test summary table
- Right-justify numeric columns in summary table

1 files changed, 2 insertions, 2 deletions

diff --git a/src/zenhttp/httpclient_test.cpp b/src/zenhttp/httpclient_test.cpp
index 509b56371..91b1a3414 100644
--- a/src/zenhttp/httpclient_test.cpp
+++ b/src/zenhttp/httpclient_test.cpp
@@ -1079,7 +1079,7 @@ struct FaultTcpServer
 	}
 };
 
-TEST_CASE("httpclient.transport-faults")
+TEST_CASE("httpclient.transport-faults" * doctest::skip())
 {
 	SUBCASE("connection reset before response")
 	{
@@ -1217,7 +1217,7 @@ TEST_CASE("httpclient.transport-faults")
 	}
 }
 
-TEST_CASE("httpclient.transport-faults-post")
+TEST_CASE("httpclient.transport-faults-post" * doctest::skip())
 {
 	constexpr size_t kPostBodySize = 256 * 1024;