chore: project scaffold, build config, scripts and README

Bun + SvelteKit (static adapter) + Electron project files, icon resources,
dev/e2e/bench scripts and the README documenting the app.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

scripts/icons.sh

@@ -0,0 +1,16 @@
+#!/bin/sh
+# Render resources/icon.svg into every icon file the app and its installers use.
+# Needs rsvg-convert (librsvg) and ImageMagick. The results are committed, so building doesn't need these.
+set -e
+cd "$(dirname "$0")/../resources"
+mkdir -p icons
+for s in 16 24 32 48 64 128 256 512 1024; do
+  rsvg-convert -w $s -h $s icon.svg -o icons/${s}x${s}.png
+done
+cp icons/1024x1024.png icon.png                       # electron-builder: macOS .icns is made from this
+magick icons/16x16.png icons/24x24.png icons/32x32.png icons/48x48.png \
+  icons/64x64.png icons/128x128.png icons/256x256.png icon.ico   # Windows
+rm icons/1024x1024.png                                 # Linux sizes stop at 512
+cp icon.svg ../static/icon.svg                         # the welcome screen shows it
+cp icons/64x64.png ../static/favicon.png
+echo "icons written to resources/ and static/"