fix(input): resolve SDL3Mouse ODR violation causing dropped clicks

[fbraz3]

Description

Fixes #231

Changes

• Add missing #include "PreRTS.h" in SDL3Mouse.cpp for both Generals and Zero Hour to resolve an ODR violation regarding the DUMP_PERF_STATS macro, ensuring the SubsystemInterface layout is correctly sized so the virtual update() dispatch executes.

[costin-alupului]

Thanks for digging into this @fbraz3 — the ODR violation is a real find and worth fixing on its own.

I built this branch (fix/issue-231-sdl3mouse-odr-violation, confirmed the GameCommon.h include is compiled into the SDL3Mouse.cpp object) on top of current main and tested on macOS 26 / M4 Max / native arm64. Unfortunately it does not change the #231 behavior — same as before the fix:

• Drag-box selection rectangle still draws with a visible delay (~1s of dragging before it appears).
• Moving units still cannot be reliably clicked — a moving dozer misses on the trailing edge (the unit vacates the clicked spot before the click resolves).
• Stationary-unit selection still works (with the same delay), and control-group hotkeys are still instant.

So the ODR fix is good to land as its own correctness fix, but #231 is not resolved by it.

Worth noting re: the "dropped clicks" framing — from testing, clicks are not actually dropped: stationary units always select. The user-visible issue is a consistent delay between the mouse click and when the game acts on it; moving units only appear to drop because they move off the clicked spot during that delay. Critically, keyboard input has no such delay (control groups select instantly), which points at something specific to the mouse-event path rather than the shared message/logic pipeline. Full problem definition is in the updated #231 body.

Happy to test any follow-up.