skyRenderTri/skyRenderFull emit the sky as a verbatim N64 RDP triangle
command chopped into G_RDPHALF_* immediates, which fast3d deliberately
no-ops -> Surface/Statue/Streets skies render solid black.
Behind #ifdef PORT, substitute a screen-space gSPVertex + gSP1Triangle/
gSP2Triangles emit built from the already-projected SkyRelated38 verts
(new helper skyPortRenderPoly, ortho matrices via dynAllocate*). N64 path
unchanged under #else. Pure RSP-idiom substitution, no behavioural change.
Links 243/243. Render check owed on a display: -level_22 frame ~360.
findings.md D176(a) M-46; porting-notes.mdD.