builds cmd refactor (#975)

- Bugfix: `builds download` partial-block fetch decisions now account for build storage host latency
- Bugfix: Transfer rate displays in `builds` commands now smooth correctly
- Split `buildstorageoperations.cpp` (8.5k lines) into per-operation TUs: buildinspect, buildprimecache, buildstorageresolve, buildupdatefolder, builduploadfolder, buildvalidatebuildpart; stats moved to buildstoragestats.h.
- FilteredRate extracted to zenutil.
- BuildsCommand shared state consolidated into a BuildsConfiguration struct; subcommands inherit from BuildsSubCmdBase holding a `const BuildsConfiguration&` instead of a `BuildsCommand&`.
- `ProgressBar` renamed to `ConsoleProgressBar`; mode enum (`ConsoleProgressMode`) lifted to namespace scope;  `PushLogOperation`/`PopLogOperation`/`ForceLinebreak` promoted to virtuals on `ProgressBase`.
- Free-function wrappers (`UploadFolder`, `DownloadFolder`, `ValidateBuildPart`) added around the existing operation classes so callers stop reimplementing setup + stats logging.

2 files changed, 40 insertions, 0 deletions

diff --git a/src/zenutil/include/zenutil/filteredrate.h b/src/zenutil/include/zenutil/filteredrate.h
new file mode 100644
index 000000000..3349823d0
--- /dev/null
+++ b/src/zenutil/include/zenutil/filteredrate.h
@@ -0,0 +1,37 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#pragma once
+
+#include <zencore/timer.h>
+
+#include <atomic>
+#include <cstdint>
+
+namespace zen {
+
+class FilteredRate
+{
+public:
+	FilteredRate() {}
+
+	void Start();
+	void Stop();
+	void Update(uint64_t Count);
+
+	uint64_t GetCurrent() const;
+	uint64_t GetElapsedTimeUS() const;
+	bool	 IsActive() const;
+
+private:
+	Stopwatch			  Timer;
+	std::atomic<uint64_t> StartTimeUS		= (uint64_t)-1;
+	std::atomic<uint64_t> EndTimeUS			= (uint64_t)-1;
+	std::atomic<uint64_t> LastTimeUS		= (uint64_t)-1;
+	uint64_t			  LastCount			= 0;
+	uint64_t			  LastPerSecond		= 0;
+	uint64_t			  FilteredPerSecond = 0;
+};
+
+uint64_t GetBytesPerSecond(uint64_t ElapsedWallTimeUS, uint64_t Count);
+
+}  // namespace zen
diff --git a/src/zenutil/include/zenutil/progress.h b/src/zenutil/include/zenutil/progress.h
index 6a137ae9c..4103723b3 100644
--- a/src/zenutil/include/zenutil/progress.h
+++ b/src/zenutil/include/zenutil/progress.h
@@ -16,6 +16,8 @@ public:
 
 	virtual void	 SetLogOperationName(std::string_view Name)						 = 0;
 	virtual void	 SetLogOperationProgress(uint32_t StepIndex, uint32_t StepCount) = 0;
+	virtual void	 PushLogOperation(std::string_view Name)						 = 0;
+	virtual void	 PopLogOperation()												 = 0;
 	virtual uint32_t GetProgressUpdateDelayMS() const								 = 0;
 
 	class ProgressBar
@@ -54,6 +56,7 @@ public:
 		virtual ~ProgressBar() = default;
 
 		virtual void UpdateState(const State& NewState, bool DoLinebreak) = 0;
+		virtual void ForceLinebreak()									  = 0;
 		virtual void Finish()											  = 0;
 	};