PHLEGM v8 Checkpoint 69 - CHOP isometric spin / metallic hidden-surface renderer

Only PHLEGM components change; no DSWS application code or runtime dependency.
At MAIN load, load cfg/instructions/<$project>.chop.phlegm and compile
all silhouettes, metallic render 16 isometric yaw frames for each unique model.
The camera rotates horizontally about vertical Y at a fixed isometric elevation.
True surfaces are rasterized with a depth buffer; backfacing polygons are
culled by each face's signed outward axis normal, NOT triangle winding.
Visible black wireframe outlines are drawn only around the four perimeter
edges of each greedy-meshed quad and are depth-tested against all filled
polygons, concealing backfacing AND occluded edges, with no triangle diagonals.
Windows: native child-window timer advances cached GDI frame bitmaps.
Linux: GLib timeout replaces the icon-view pixbuf column in-place, preserving
selection, scroll position and current hierarchy. Cached pixbufs per frame.
No silhouette recompilation or shading during GUI paint. No Python shipped.
Full native FreeBASIC compilation and GUI tests are still required.
