- Derive As from the provided longitudinal bars instead of taking it as
input; drop the redundant As_bars output and update tests.
- Draw a fixed schematic 1 in cover and pin the bottom bars to the
stirrup's bottom leg so the figure no longer depends on cover or d.
- Fixed stirrup stroke with a rounded 3 pt corner radius.
- Right-align the figure, constrain its caption to the image width, and
shorten the caption to "Beam cross-section".
- Document input.yaml fields.
Add reinforcement inputs (cover, stirrup size/spacing, longitudinal and
top bar size/count) and emit the derived bar geometry from calc.py.
beam_section.py renders a native Typst drawing of the section to
assets/beam-section.typ, which concrete-beam.typ imports as a figure.
Effective depth d remains authoritative for the tension-steel position.
