PHLEGM v8 CHECKPOINT 68 — CHOP geometry/recompiler architecture

Scope: repurpose the geometric purpose of DSWS CHOP, not DSWS application code.
The sole library filename is lowercase src/lib/chop.lib.
chop.lib is platform-neutral FreeBASIC source; no DSWS assets/runtime installed.

At MAIN load, after master records determine <$project> and after instruction
bootstrap, PHLEGM.bas invokes the GUI library's GuiBakeMainIcons exactly once.
It opens cfg/instructions/<$project>.chop.phlegm, parses and validates three
orthogonal 16x16 silhouettes per model, builds a subtractive voxel hull, applies
optional mirrored X/Y/Z axes through occupancy intersection, extracts only
exposed surfaces, greedily merges coplanar surfaces to two triangles/quad,
then picks the highest-fidelity grid meeting each model's polygon budget.

The generic CHOP compiler is chop.lib; icons-models.lib is an application
adapter for identity, color and one-time cached ARGB raster baking. icons.lib
reuses these immutable images; GUI paint callbacks never recompile geometry.
Windows uses GDI pixels, Linux uses Cairo pixels, with the same source mesh.
No machine/CPU micro-code or session state is modified by icon baking.

An ordinary folder remains trapezoidal; Up/Back folder uses a separate
silhouette with two subtractive dot holes. ZIP now uses a left-hand vise
vertically squeezing a box, not a folder/badge. ZIP metadata variants 32..39
all reuse this single iconic silhouette/raster until additional variations
are defined in .phlegm. No source-level ZIP shape is hard-coded into CHOP.

The previous PHLEGM.bezier.phlegm file is retained for historical compatibility
but no longer drives icons. Master record path.chop.definition.format is the
canonical new definition filename rule.

Constraints/limitations:
 - Three projections cannot prove enclosed or invisible cavities.
 - View silhouettes with '.' holes produce subtractive through-holes.
 - Symmetric reflection keeps only cells allowed by all reflected views.
 - No mesh is accepted if it exceeds its declared triangle budget.
 - 16^3 is the maximum input occupancy grid; chooses <=16 fidelity if needed.

Native developer test: tests/chop-selftest.bas (requires FreeBASIC)
Example: fbc -lang fb -x chop-selftest tests/chop-selftest.bas
Then run with cfg/instructions/PHLEGM.chop.phlegm.

Native compilation and graphical runtime tests must be performed on supported
targets; checkpoint delivery alone does NOT establish successful builds.
