Regen typeset splits at 250 PPI; rename structured->uniform; strengthen prompt
- Bump render PPI 150->250 in generate_typeset.py; increase margins y:8->12pt
- Rename typeset_structured_* splits to typeset_uniform_* (mode=uniform vs mixed)
- Consolidate generate_handwritten.py into generate_typeset.py; drop dead
generate_mixed.py and generate_handwritten.py entrypoints
- Regenerate typeset_uniform (10k train) and typeset_mixed (20k train) at new PPI
- Strengthen PROMPT: require raw Typst output, explicitly forbid LaTeX
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>