Each dialog window (Page Setup, DimStyle, TextStyle, TableStyle,
MLineStyle, PlotStyle, Layout Manager, Shortcuts) is now a proper
window-filling layout in its own src/ui/<dialog>.rs file.
Pattern: toolbar strip at top + vertical separator + scrollable
content filling the rest — no modal card, no backdrop, no stack[].
Matches the existing Layer Manager window pattern.
Removed ~1600 lines of old overlay functions from view.rs.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
