fix(render): iter 75 — stage cm + cm-super for cmcsc10/cmti10 (fix nf-fallback glyph overlap)
SVG diff of ag-0018 (tngl vs gh-pages) shows tngl rendering with nf2/nf3
(dvisvgm 'no font' fallback) where gh-pages uses cmcsc10 and cmti10. These
Computer Modern variants aren't in texlive.bin.core's kpathsea path at
runtime, so dvisvgm substitutes generic shapes with wrong metrics → text
glyphs overlap, especially in algorithm trees.
Stage the cm + cm-super packages via stage_tl_pkg so the matching TFM + PFB
land in FOREST_TEX_DIR. Render-only change, no depot rebuild (~7m total).
Refs #2
[AGENT: kael]