Theme · Importing: VS Code themes read into Ely's palette, code palettes to choose

settings::read_vscode_theme reads a VS Code color theme, comments and
trailing commas and all: its type picks the mode, its colors and token
scopes name what they give, and the rest keep Ely's palette of that mode.
settings::ThemeImporter takes one dropped or browsed for, shows its name,
mode and count, and hands it over on Apply; a file that does not read
says why. theme::syntax_themes offers Ely's code colors, Quiet and Paper,
chosen through settings::SyntaxThemePicker, radio cards with a line of
code in each palette. A card's words now shrink as a plain block, so a
preview wraps inside the card at 280px.

tasks/ch31-43.md

@@ -261,8 +261,8 @@
 
 ## T39b Theme · Importing
 
-- [ ] ThemeImporter — VS Code theme JSON
-- [ ] SyntaxThemes
+- [x] ThemeImporter — VS Code theme JSON → `settings::ThemeImporter` on `settings::read_vscode_theme`
+- [x] SyntaxThemes → `theme::syntax_themes`, chosen through `settings::SyntaxThemePicker`
 
 ## T39c Theme · Platform