Add a Shape Library dialog (Nest > Shape Library) for creating drawings
from built-in parametric shapes. Supports configuration presets loaded
from JSON files — ships with 136 standard pipe flanges. Parameters use
TextBox inputs with architectural unit parsing (feet/inches, fractions).
- ShapeLibraryForm with split layout: shape list, preview, parameters
- ShapePreviewControl for auto-zoom rendering with info overlay
- ArchUnits utility for parsing architectural measurements
- SetPreviewDefaults() on all ShapeDefinition subclasses
- Convention-based config discovery (Configurations/{ShapeName}.json)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
