0.9.0

[0.9.0] - 2026-09-20

Breaking release: ThemeColors gains a required field, Style loses one field
and gains another mandatory one, and MapSettings drops its two-slot style vector.

Added

• ThemeColors::marker, a new color role for a lasting "this is marked"
  indicator: a node's persistent state (halo/blink/orbit, started
  through Map::node) and a plain marker set with Map::update_marker.
  Deliberately distinct from selected (which node the pointer is nearest,
  right now) and alert (a one-off event playing out). All 15 built-in
  themes define it.
• ThemeColors::background, so the map canvas's background now resolves
  from the active MapTheme for the current ColorMode, exactly like every
  other role, instead of always following the host application's own
  egui::Visuals.
• New built-in theme Theme::SystemDefault (renamed from the working name
  EguiDefault), now the enum's #[default] variant, first in the list.
  Its colors are sourced directly from egui::Visuals::dark()/light()
  (hyperlink_color, noninteractive.bg_stroke, warn_fg_color,
  error_fg_color, strong_text_color()), with selected boosted in Dark
  mode to stay at least as saturated as marker.
• RegionLabel and the LabelTemplate trait: a new kind of label anchored
  to an area of the map rather than to a single node. Unlike node names and
  MapLabels, a region label's font size scales with zoom instead of
  staying screen-constant, and it is always painted first (a background
  layer, behind everything else). Glyph layout is cached per
  (text, rounded size, font family), so a theme or alpha change never
  invalidates the cache. New API: Map::add_region_labels,
  Map::set_label_template, Style::region_label_font (a mandatory
  FontId — both family and size are read directly by the built-in
  renderer).
• Viewport culling for region labels: a label whose projected center falls
  well outside the visible rect (plus a margin scaled to the current font
  size) is skipped before any layout or paint work happens, instead of
  being laid out and painted every frame regardless of visibility.
• theme_gallery/<Theme>.svg: one self-contained SVG preview per theme
  (light and dark side by side), generated by a new standalone Rust tool,
  scripts/generate_theme_gallery, which replaces the previous Python
  script and the single combined theme_gallery.png. THEMES.md now
  embeds each theme's own SVG inline and lists a Background column
  alongside the other five color roles.

Changed

• All 15 built-in themes were redesigned for visual cohesion across the
  catalog: node/text/background (and, for the 14 non-default themes,
  alert/selected/segment too) were reworked, and every theme now
  defines its own marker (same hue as alert, half its saturation) and
  background.
• Flat markers (Map::update_marker) now resolve to ThemeColors::marker
  instead of ThemeColors::alert — a visible change for anyone using flat
  markers without installing a custom MapTheme.
• Node background chips (NodeContext::background_color) now use
  extreme_bg_color from the host egui::Visuals instead of
  faint_bg_color, for better contrast against the map canvas.
• Per-node theme and background-color lookups are now resolved once per
  paint batch instead of once per role per node, cutting redundant calls
  to Theme::colors() and egui::Context::theme() in busy scenes.
• MapSettings.styles: Vec<Style> collapsed to a single
  MapSettings.style: Style (breaking) — the two light/dark slots held
  identical data once background_color moved out of Style (see
  Removed). Map's internal current_index: usize became dark_mode: bool, and the now-trivial Map::current_style() helper was removed.

Fixed

• ArticCyan and SolarAmber had their entire Light/Dark color blocks
  transposed, making text illegible against light backgrounds. Added a
  permanent WCAG AA (4.5:1) contrast regression test covering all 30
  (theme, mode) combinations.
• The THEMES.md/SVG generator's theme.rs parser normalizes \r\n line
  endings before matching, fixing a bug where a stray #[default] token
  leaked into a theme's tagline on CRLF (Windows) checkouts.
• Stale documentation referencing colors and fields removed in earlier
  releases (a Style::alert_color that hasn't existed since 0.6.0, a
  NodeStyle::fill_color from a much older version of the crate) rewritten
  to describe current behavior.

Removed

• Style::background_color (breaking) — the canvas background is now
  ThemeColors::background on the active MapTheme; nothing ever actually
  painted a background from this field (the canvas never had one of its
  own), so removing it drops dead state rather than changing rendering.
• MapSettings::region_label_size (breaking) — superseded by the now
  mandatory Style::region_label_font.size.

Full Changelog: 0.5.1...0.9.0