Phase 4.1. Handle / u64 keys dominate the hot maps (block_defn,
hatch / image / mesh caches, draw-depth map, viewport wire caches);
the default SipHash is wasted work on integer keys. Alias the std
types to rustc_hash::FxHashMap / FxHashSet crate-wide so every map and
set — including the cross-module draw-depth map shared between scene
and the GPU pipelines — uses the faster hasher consistently.
Mechanical: no behavioural change. Constructors moved from ::new() to
::default() (Fx variants carry no RandomState). Build + 13 tests green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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>
