Make the logger timestamp portable (#401)

logger.hpp pulled in <sys/time.h> and used gettimeofday and localtime_r,
which do not exist on MSVC. Build the timestamp from std::chrono instead
and use localtime_s on MSVC. The output format is unchanged: <colour>-
HH:MM:SS.mmm LEVEL: message<reset>. The unused __SHORT_FORM_OF_FILE__
helper now also strips backslash separators. Add logger tests that pin
the timestamp and line format.

closes #394

Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>

src/logger.test.cpp

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: MPL-2.0
+#include "aare/logger.hpp"
+
+#include <catch2/catch_test_macros.hpp>
+#include <catch2/matchers/catch_matchers_string.hpp>
+
+#include <iostream>
+#include <sstream>
+#include <string>
+
+using Catch::Matchers::EndsWith;
+using Catch::Matchers::Matches;
+using Catch::Matchers::StartsWith;
+
+TEST_CASE("Log timestamp is HH:MM:SS.mmm", "[logger]") {
+    const std::string ts = aare::Logger::Timestamp();
+    REQUIRE_THAT(ts, Matches(R"(\d{2}:\d{2}:\d{2}\.\d{3})"));
+}
+
+TEST_CASE("short_file_name strips both kinds of directory separators",
+          "[logger]") {
+    REQUIRE(std::string(aare::short_file_name("/a/b/File.cpp")) == "File.cpp");
+    REQUIRE(std::string(aare::short_file_name("C:\\a\\b\\File.cpp")) ==
+            "File.cpp");
+    REQUIRE(std::string(aare::short_file_name("File.cpp")) == "File.cpp");
+}
+
+TEST_CASE("LOG writes one coloured line with timestamp and level", "[logger]") {
+    std::ostringstream captured;
+    auto *previous = std::clog.rdbuf(captured.rdbuf());
+    LOG(aare::logWARNING) << "hello " << 42;
+    std::clog.rdbuf(previous);
+
+    const std::string line = captured.str();
+    // <colour>- HH:MM:SS.mmm WARNING: hello 42<reset>\n
+    REQUIRE_THAT(line, StartsWith(std::string(YELLOW BOLD) + "- "));
+    REQUIRE_THAT(line, Matches(std::string("\x1b\\[33m\x1b\\[1m- ") +
+                               R"(\d{2}:\d{2}:\d{2}\.\d{3} WARNING: hello 42)" +
+                               "\x1b\\[0m\n"));
+    REQUIRE_THAT(line, EndsWith(std::string(RESET) + "\n"));
+}