v0.3.0 — Linux support

v0.3.0 — Linux support

JUSDecomp now runs natively on Linux, with the same feature set as the
Windows app: the recompiled runner (SDL2 + OpenGL 4.3 compute renderer,
software-renderer fallback), a GTK launcher with full parity, online WiFi
Battle over Wiimmfi, and runtime mods.

Linux quick start (source build — see
docs/LINUX.md):

sudo pacman -S --needed cmake ninja gcc sdl2 gtk3 python git   # Arch/Omarchy
# or the equivalent SDL2 + GTK3 dev packages on your distro
tools/scripts/build_linux.sh
launcher/build-linux/JUSDecomp

The build verifies your ROM dump, compiles the runner and launcher, and
pre-compiles the native code cache (328 overlay banks) so the game boots
at full speed — no first-session convergence, no background compiler.

Framerate fix included: without the pre-seed, a fresh Linux install ran
the RAM overlays on the Tier-3 interpreter (~30 fps) and compiled native
banks in the background for minutes while playing. Verified result with the
pre-seed: 59.4 fps at boot, zero interpreted instructions, idle compiler.
If a Linux install ever runs at about half framerate, run
python3 tools/scripts/live_preseed.py and relaunch.

Windows players: nothing changes — download JUSDecomp-0.3.0.zip
below, extract, run JUSDecomp.exe, and select your legally dumped ROM.

Known issues: unchanged from v0.2.2 (intro-video FPS dips on slower
machines, deck-builder FPS dips, occasional online micro-stutters,
friend-code refresh on relaunch, minor visual glitches on some stages). On
Linux, the ARM7 Wi-Fi driver pages converge in-session during the first
minutes of online play.