Symbolize crash reports with a first-party tool

Adds tools/symbolize_crash.cpp, built alongside the game as a console exe:
it reads a crash_report_*.txt written by writeExceptionBacktrace and prints
the backtrace with function names, source lines and inlined frames, in call
order, coloured when standard output is a console.

Symbols come from DbgHelp against the build's PDB rather than an external
symbolizer. SymLoadModuleEx takes the runtime base out of the report's
module table, so the relocation arithmetic /DYNAMICBASE forces on us is
DbgHelp's problem now; a report predating the module table loads at the
image's preferred base, which is where it ran. Verified under Wine: PDB
line info and inline traces both resolve.

The tool wants C++23 (std::print, std::format) where the game is C++17, so
the standard is set on the target alone. Both MSVC 19.51 and clang-cl build
it clean in all three configurations.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

sgp/debug_win_util.cpp

@@ -216,7 +216,7 @@ void StackTrace::PrintBacktrace(const char* msg) {
 // and take the report down with it. So this path is deliberately heap-free: only
 // stack buffers and raw Win32. It emits runtime addresses plus the module table
 // needed to make sense of them; symbolize offline against the build's PDB:
-//   llvm-symbolizer --obj=JA2.exe --adjust-vma=$((<JA2.exe base> - 0x400000)) <addr>
+//   symbolize_crash crash_report_001.txt JA2.exe
 namespace sgp {
 
 // Stamped into every crash report so a report maps to the exact build's PDB.