Perf: IntSurf_LineOn2S → std::vector + hot-path hash-op cleanups #3440

Job	Run time
Check code formatting	44s
Check for non-ASCII characters	47s
Prepare and Build on Windows with MSVC (x64)	26m 33s
Prepare and Build on Ubuntu with Clang (x64)	24m 29s
Prepare and Build on macOS with Clang (x64)	18m 8s
Test on macOS (x64)	43s
Run GTest on macOS with Clang (x64)	1m 14s
Regression Test on macOS (x64)	17s
Test on Linux with Clang (x64)	28m 48s
Run GTest on Linux with Clang (x64)	1m 55s
Prepare and Build on Ubuntu with GCC (No PCH)	39m 45s
Run GTest on Windows with MSVC (x64)	1m 40s
Test on Windows (x64)	34m 34s
Regression Test on Linux with Clang (x64)	2m 4s
Regression Test on Windows (x64)	4m 55s
Run GTest on Ubuntu with GCC (No PCH, Debug)	7m 40s
Summarize Test Results	3m 20s
Build Documentation	-1s
	3h 17m 35s

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