Logging and diagnostics improvements (#941)

Core logging and system diagnostics improvements, extracted from the compute branch.

### Logging
- **Elapsed timestamps**: Console log now shows elapsed time since launch `[HH:MM:SS.mmm]` instead of full date/time; file logging is unchanged
- **Short level names**: 3-letter short level names (`trc`/`dbg`/`inf`/`wrn`/`err`/`crt`) used by both console and file formatters via `ShortToStringView()`
- **Consistent field order**: Standardized to `[timestamp] [level] [logger]` across both console and file formatters
- **Slim LogMessage/LogPoint**: Remove redundant fields from `LogMessage` (derive level/source from `LogPoint`), flatten `LogPoint` to inline filename/line fields, shrink `LogLevel` to `int8_t` with `static_assert(sizeof(LogPoint) <= 32)`
- **Remove default member initializers** and static default `LogPoint` from `LogMessage` — all fields initialized by constructor
- **LoggerRef string constructor**: Convenience constructor accepting a string directly
- **Fix SendMessage macro collision**: Replace `thread.h` include in `logmsg.h` with a forward declaration of `GetCurrentThreadId()` to avoid pulling in `windows.h` transitively

### System Diagnostics
- **Cache static system metrics**: Add `RefreshDynamicSystemMetrics()` that only queries values that change at runtime (available memory, uptime, swap). `SystemMetricsTracker` snapshots full `GetSystemMetrics()` once at construction and reuses cached topology/total memory on each `Query()`, avoiding repeated `GetLogicalProcessorInformationEx` traversal on Windows, `/proc/cpuinfo` parsing on Linux, and `sysctl` topology calls on macOS

1 files changed, 95 insertions, 2 deletions

diff --git a/src/zencore/system.cpp b/src/zencore/system.cpp
index 6909e1a9b..486050d83 100644
--- a/src/zencore/system.cpp
+++ b/src/zencore/system.cpp
@@ -148,6 +148,18 @@ GetSystemMetrics()
 	return Metrics;
 }
 
+void
+RefreshDynamicSystemMetrics(SystemMetrics& Metrics)
+{
+	MEMORYSTATUSEX MemStatus{.dwLength = sizeof(MEMORYSTATUSEX)};
+	GlobalMemoryStatusEx(&MemStatus);
+
+	Metrics.AvailSystemMemoryMiB  = MemStatus.ullAvailPhys / 1024 / 1024;
+	Metrics.AvailVirtualMemoryMiB = MemStatus.ullAvailVirtual / 1024 / 1024;
+	Metrics.AvailPageFileMiB	  = MemStatus.ullAvailPageFile / 1024 / 1024;
+	Metrics.UptimeSeconds		  = GetTickCount64() / 1000;
+}
+
 std::vector<std::string>
 GetLocalIpAddresses()
 {
@@ -324,6 +336,51 @@ GetSystemMetrics()
 
 	return Metrics;
 }
+
+void
+RefreshDynamicSystemMetrics(SystemMetrics& Metrics)
+{
+	long PageSize	= sysconf(_SC_PAGE_SIZE);
+	long AvailPages = sysconf(_SC_AVPHYS_PAGES);
+
+	if (AvailPages > 0 && PageSize > 0)
+	{
+		Metrics.AvailSystemMemoryMiB  = (AvailPages * PageSize) / 1024 / 1024;
+		Metrics.AvailVirtualMemoryMiB = Metrics.AvailSystemMemoryMiB;
+	}
+
+	if (FILE* UptimeFile = fopen("/proc/uptime", "r"))
+	{
+		double UptimeSec = 0;
+		if (fscanf(UptimeFile, "%lf", &UptimeSec) == 1)
+		{
+			Metrics.UptimeSeconds = static_cast<uint64_t>(UptimeSec);
+		}
+		fclose(UptimeFile);
+	}
+
+	if (FILE* MemInfo = fopen("/proc/meminfo", "r"))
+	{
+		char Line[256];
+		long SwapFree = 0;
+
+		while (fgets(Line, sizeof(Line), MemInfo))
+		{
+			if (strncmp(Line, "SwapFree:", 9) == 0)
+			{
+				sscanf(Line, "SwapFree: %ld kB", &SwapFree);
+				break;
+			}
+		}
+		fclose(MemInfo);
+
+		if (SwapFree > 0)
+		{
+			Metrics.AvailPageFileMiB = SwapFree / 1024;
+		}
+	}
+}
+
 #elif ZEN_PLATFORM_MAC
 std::string
 GetMachineName()
@@ -398,6 +455,36 @@ GetSystemMetrics()
 
 	return Metrics;
 }
+
+void
+RefreshDynamicSystemMetrics(SystemMetrics& Metrics)
+{
+	vm_size_t PageSize = 0;
+	host_page_size(mach_host_self(), &PageSize);
+
+	vm_statistics64_data_t VmStats;
+	mach_msg_type_number_t InfoCount = sizeof(VmStats) / sizeof(natural_t);
+	host_statistics64(mach_host_self(), HOST_VM_INFO64, (host_info64_t)&VmStats, &InfoCount);
+
+	uint64_t FreeMemory			  = (uint64_t)(VmStats.free_count + VmStats.inactive_count) * PageSize;
+	Metrics.AvailSystemMemoryMiB  = FreeMemory / 1024 / 1024;
+	Metrics.AvailVirtualMemoryMiB = Metrics.VirtualMemoryMiB;
+
+	xsw_usage SwapUsage;
+	size_t	  Size = sizeof(SwapUsage);
+	sysctlbyname("vm.swapusage", &SwapUsage, &Size, nullptr, 0);
+	Metrics.AvailPageFileMiB = (SwapUsage.xsu_total - SwapUsage.xsu_used) / 1024 / 1024;
+
+	struct timeval BootTime
+	{
+	};
+	Size = sizeof(BootTime);
+	if (sysctlbyname("kern.boottime", &BootTime, &Size, nullptr, 0) == 0)
+	{
+		Metrics.UptimeSeconds = static_cast<uint64_t>(time(nullptr) - BootTime.tv_sec);
+	}
+}
+
 #else
 #	error "Unknown platform"
 #endif
@@ -655,11 +742,16 @@ struct SystemMetricsTracker::Impl
 
 	std::mutex				  Mutex;
 	CpuSampler				  Sampler;
+	SystemMetrics			  CachedMetrics;
 	float					  CachedCpuPercent = 0.0f;
 	Clock::time_point		  NextSampleTime   = Clock::now();
 	std::chrono::milliseconds MinInterval;
 
-	explicit Impl(std::chrono::milliseconds InMinInterval) : MinInterval(InMinInterval) {}
+	explicit Impl(std::chrono::milliseconds InMinInterval) : MinInterval(InMinInterval)
+	{
+		// Capture topology and total memory once; these don't change at runtime
+		CachedMetrics = GetSystemMetrics();
+	}
 
 	float SampleCpu()
 	{
@@ -683,7 +775,8 @@ ExtendedSystemMetrics
 SystemMetricsTracker::Query()
 {
 	ExtendedSystemMetrics Metrics;
-	static_cast<SystemMetrics&>(Metrics) = GetSystemMetrics();
+	static_cast<SystemMetrics&>(Metrics) = m_Impl->CachedMetrics;
+	RefreshDynamicSystemMetrics(Metrics);
 
 	std::lock_guard Lock(m_Impl->Mutex);
 	Metrics.CpuUsagePercent = m_Impl->SampleCpu();