app icon: lynx (owner's ArtCraft drawing), Dock/taskbar/launcher wiring, palette docs

- assets/app-icon/: lightcraft.svg (master), lightcraft-small.svg, 1024 PNG, macOS 512 PNG,
  .icns, .ico, hicolor theme (ai.storyteller.lightcraft), LICENSE.txt, README (palette,
  geometry, provenance, files)
- packaging/icons.sh regenerates everything (resvg, iconutil, new `cargo xtask ico`)
- apps/lightcraft: runtime window/Dock icon + Wayland app id; build.rs embeds the .ico and
  VERSIONINFO into lightcraft.exe (winresource, Windows targets only)
- packaging/linux/ai.storyteller.lightcraft.desktop
- ATTRIBUTION.md entry; icon at the top of README

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

packaging/icons.sh

@@ -0,0 +1,59 @@
+#!/usr/bin/env bash
+# Regenerate every app icon file from assets/app-icon/lightcraft.svg.
+#
+# Needs: resvg (brew install resvg / cargo install resvg). On macOS, iconutil also writes the
+# .icns. The outputs are committed, so building and packaging never need these tools.
+#
+#   packaging/icons.sh
+set -euo pipefail
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+DIR="$ROOT/assets/app-icon"
+SVG="$DIR/lightcraft.svg"
+ID="ai.storyteller.lightcraft"
+TMP="$(mktemp -d)"
+trap 'rm -rf "$TMP"' EXIT
+
+command -v resvg >/dev/null || { echo "error: resvg not found (brew install resvg)" >&2; exit 1; }
+
+# The SVG is the full-bleed 512 tile (rx=112). Windows and Linux use it as is, so the lynx reads at
+# 16-48 px. macOS icons follow Apple's grid: an 824/1024 body with a transparent margin, made by
+# widening the viewBox (512 / 0.805 = 636, so 62 units each side).
+MAC="$TMP/macos.svg"
+sed 's/viewBox="0 0 512 512"/viewBox="-62 -62 636 636"/' "$SVG" >"$MAC"
+grep -q 'viewBox="-62 -62 636 636"' "$MAC" || { echo "error: unexpected viewBox in $SVG" >&2; exit 1; }
+
+render() { resvg -w "$2" -h "$2" "$1" "$3" </dev/null; }
+
+render "$SVG" 1024 "$DIR/lightcraft-1024.png"
+# Runtime window/Dock icon on macOS (embedded by apps/lightcraft/src/main.rs).
+render "$MAC" 512 "$DIR/lightcraft-macos-512.png"
+
+# Linux hicolor theme (also the runtime window icon on Windows and Linux: 256x256).
+for s in 16 24 32 48 64 128 256 512; do
+  mkdir -p "$DIR/hicolor/${s}x${s}/apps"
+  render "$SVG" "$s" "$DIR/hicolor/${s}x${s}/apps/$ID.png"
+done
+mkdir -p "$DIR/hicolor/scalable/apps"
+cp "$DIR/lightcraft-small.svg" "$DIR/hicolor/scalable/apps/$ID.svg"
+
+# Windows .ico.
+ICO_PNGS=()
+for s in 16 20 24 32 40 48 64 128 256; do
+  render "$SVG" "$s" "$TMP/ico-$s.png"
+  ICO_PNGS+=("$TMP/ico-$s.png")
+done
+(cd "$ROOT" && cargo run -q -p xtask -- ico "$DIR/lightcraft.ico" "${ICO_PNGS[@]}")
+
+# macOS .icns.
+if command -v iconutil >/dev/null; then
+  SET="$TMP/lightcraft.iconset"
+  mkdir -p "$SET"
+  for s in 16 32 128 256 512; do
+    render "$MAC" "$s" "$SET/icon_${s}x${s}.png"
+    render "$MAC" $((s * 2)) "$SET/icon_${s}x${s}@2x.png"
+  done
+  iconutil -c icns -o "$DIR/lightcraft.icns" "$SET"
+else
+  echo "warning: iconutil not found (macOS only); lightcraft.icns not regenerated" >&2
+fi
+echo "icons written to $DIR"

packaging/linux/ai.storyteller.lightcraft.desktop

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+[Desktop Entry]
+Type=Application
+Name=LightCraft
+GenericName=Photo Library and Raw Developer
+Comment=Organise photos and develop raw files, non-destructively
+Exec=lightcraft %F
+Icon=ai.storyteller.lightcraft
+Terminal=false
+Categories=Graphics;2DGraphics;RasterGraphics;Photography;
+Keywords=photo;raw;camera;library;develop;
+StartupWMClass=ai.storyteller.lightcraft
+MimeType=image/jpeg;image/png;image/tiff;image/webp;image/x-adobe-dng;image/x-sony-arw;image/x-canon-cr2;image/x-canon-cr3;image/x-nikon-nef;image/x-fuji-raf;image/x-olympus-orf;image/x-panasonic-rw2;image/x-pentax-pef;