Org t-shirt apparel artwork (chest mark + back lockup)

[lesnik512]

Adds an apparel target to the brand generator: print-ready artwork for a black modern-python org t-shirt, in the two-ink cream + gold-dark colorway (the on-dark org treatment). Nothing hand-drawn — everything is generated from brand/build/ and committed.

What's new

• geometry.apparel_back(*, struct, gold) — the back-of-shirt lockup: the existing MODERN/PYTHON wordmark with modern-python.org outlined beneath it, one transparent SVG (viewBox 118 32 304 228, centered on x=270). Reuses lockup_body + outline_text (no font dependency at serve time).
• brand/build/apparel.py (render_apparel) — writes brand/apparel/:
  • chest-mark.svg / chest-mark-1050.png — the transparent chevron mark (geometry.mark), left chest, ~3.5 in @ 300 DPI.
  • back-lockup.svg / back-lockup-2400.png — the back lockup, ~8 in @ 300 DPI.
  • Wired into render.py after render_projects(); SVGs are the master, PNGs are 300 DPI fallbacks through the existing export_png/quantize path.
• brand/apparel/README.md — print spec (colorway, sizes, placement, vendor notes).
• architecture/brand-marks.md — new Apparel capability section.

The full colorway is 2 inks only (cream #f4f1e8 + gold-dark #f0b528), so the whole garment is a 2-color spot print. The design/plan bundle is in planning/changes/2026-07-04.01-org-tshirt/.

Verification

• just check-planning → planning: OK
• uv run pytest → 99 passed (new test_apparel_back_wordmark_plus_url, test_render_writes_apparel)
• render is a deterministic no-op diff apart from the four new apparel assets; rendered PNGs eyeballed against the approved mockup.

🤖 Generated with Claude Code