Draft: Add PSP port

[trulio2]

out.mp4

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PSPDEV C++ portability

PSPDEV may define std::int32_t as long, while literals and many PSP APIs
use int. Keep mixed-type calls explicit:

const auto clamped = std::clamp<std::int32_t>(value, 0, upper);
sceGuSomething(static_cast<int>(clamped));  // Only after range validation.

For formatted std::int32_t values, include <cinttypes> and use PRId32
instead of %d:

std::fprintf(stderr, "value=%" PRId32 "\n", value);