Merge origin/main into feature/iop-emulator

Preserve the branch's GS CLUT and texture cache implementation while integrating upstream thread initialization and syscall resume coverage. Build passes; 448/456 tests pass with the same eight failures reproduced on pre-merge HEAD (447/455).

ps2xRecomp/src/lib/control_flow_analyzer.cpp

@@ -135,6 +135,9 @@ namespace ps2recomp
 
         for (const auto &inst : instructions)
         {
+            // A guest-installed syscall handler runs as a separate invocation,
+            // so the scheduler resumes this thread at syscall+4 and needs an
+            // entry point there. +4, not +8: syscall has no delay slot.
             if (inst.opcode == OPCODE_SPECIAL && inst.function == SPECIAL_SYSCALL)
             {
                 queueResumeEntryTarget(inst.address + 4u);