Various bug fixes (#778)

zencore fixes:
- filesystem.cpp: ReadFile error reporting logic
- compactbinaryvalue.h: CbValue::As*String error reporting logic

zenhttp fixes:
- httpasio BindAcceptor would `return 0;` in a function returning `std::string` (UB)
- httpsys async workpool initialization race

zenstore fixes:
- cas.cpp: GetFileCasResults Results param passed by value instead of reference (large chunk results were silently lost)
- structuredcachestore.cpp: MissCount unconditionally incremented (counted hits as misses)
- cacherpc.cpp: Wrong boolean in Incomplete response array (all entries marked incomplete)
- cachedisklayer.cpp: sizeof(sizeof(...)) in two validation checks computed sizeof(size_t) instead of struct size
- buildstore.cpp: Wrong hash tracked in GC key list (BlobHash pushed twice instead of MetadataHash)
- buildstore.cpp: Removed duplicate m_LastAccessTimeUpdateCount increment in PutBlob

zenserver fixes:
- httpbuildstore.cpp: Reversed subtraction in HTTP range calculation (unsigned underflow)
- hubservice.cpp: Deadlock in Provision() calling Wake() while holding m_Lock (extracted WakeLocked helper)
- zipfs.cpp: Data race in GetFile() lazy initialization (added RwLock with shared/exclusive paths)

1 files changed, 16 insertions, 8 deletions

diff --git a/src/zencore/include/zencore/compactbinaryvalue.h b/src/zencore/include/zencore/compactbinaryvalue.h
index aa2d2821d..4ce8009b8 100644
--- a/src/zencore/include/zencore/compactbinaryvalue.h
+++ b/src/zencore/include/zencore/compactbinaryvalue.h
@@ -128,17 +128,21 @@ CbValue::AsString(CbFieldError* OutError, std::string_view Default) const
 	uint32_t		  ValueSizeByteCount;
 	const uint64_t	  ValueSize = ReadVarUInt(Chars, ValueSizeByteCount);
 
-	if (OutError)
+	if (ValueSize >= (uint64_t(1) << 31))
 	{
-		if (ValueSize >= (uint64_t(1) << 31))
+		if (OutError)
 		{
 			*OutError = CbFieldError::RangeError;
-			return Default;
 		}
+		return Default;
+	}
+
+	if (OutError)
+	{
 		*OutError = CbFieldError::None;
 	}
 
-	return std::string_view(Chars + ValueSizeByteCount, int32_t(ValueSize));
+	return std::string_view(Chars + ValueSizeByteCount, size_t(ValueSize));
 }
 
 inline std::u8string_view
@@ -148,17 +152,21 @@ CbValue::AsU8String(CbFieldError* OutError, std::u8string_view Default) const
 	uint32_t			 ValueSizeByteCount;
 	const uint64_t		 ValueSize = ReadVarUInt(Chars, ValueSizeByteCount);
 
-	if (OutError)
+	if (ValueSize >= (uint64_t(1) << 31))
 	{
-		if (ValueSize >= (uint64_t(1) << 31))
+		if (OutError)
 		{
 			*OutError = CbFieldError::RangeError;
-			return Default;
 		}
+		return Default;
+	}
+
+	if (OutError)
+	{
 		*OutError = CbFieldError::None;
 	}
 
-	return std::u8string_view(Chars + ValueSizeByteCount, int32_t(ValueSize));
+	return std::u8string_view(Chars + ValueSizeByteCount, size_t(ValueSize));
 }
 
 inline uint64_t