fix: proper macOS dock icon via .icns bundle replacement

Replace the Swift squircle hack with the correct Apple approach:
generate a proper .icns using sips + iconutil, then replace
electron.icns in the Electron bundle before launch. macOS applies
its native squircle mask + shadow from the .icns automatically.

packages/desktop/package.json

@@ -5,7 +5,7 @@
   "main": "dist/main.js",
   "scripts": {
     "build:ts": "tsc",
-    "dev": "mkdir -p build && cp ../../icon.png build/icon.png && node -e \"try{require('child_process').execSync('swift scripts/gen-dock-icon.swift',{stdio:'inherit'})}catch(e){}\" && tsc && electron .",
+    "dev": "mkdir -p build && cp ../../icon.png build/icon.png && bash scripts/gen-icns.sh && cp build/icon.icns $(find ../../node_modules -path '*/electron/dist/Electron.app/Contents/Resources/electron.icns' 2>/dev/null | head -1) 2>/dev/null; tsc && electron .",
     "prebuild": "mkdir -p build && cp ../../icon.png build/icon.png",
     "build": "tsc && electron-builder",
     "clean": "rm -rf dist dist-electron"

packages/desktop/scripts/gen-dock-icon.swift

@@ -1,21 +0,0 @@
-// Generates a squircle-masked dock icon for macOS dev mode.
-// macOS only applies the squircle mask to packaged .app bundles,
-// so app.dock.setIcon() needs a pre-masked PNG.
-
-import AppKit
-
-let src = NSImage(contentsOfFile: "build/icon.png")!
-let size = src.size
-let out = NSImage(size: size)
-
-out.lockFocus()
-let radius = size.width * 0.2237
-let path = NSBezierPath(roundedRect: NSRect(origin: .zero, size: size), xRadius: radius, yRadius: radius)
-path.addClip()
-src.draw(in: NSRect(origin: .zero, size: size), from: NSRect(origin: .zero, size: size), operation: .sourceOver, fraction: 1.0)
-out.unlockFocus()
-
-let tiff = out.tiffRepresentation!
-let rep = NSBitmapImageRep(data: tiff)!
-let png = rep.representation(using: .png, properties: [:])!
-try! png.write(to: URL(fileURLWithPath: "build/icon-dock.png"))

packages/desktop/scripts/gen-icns.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+# Generates a proper macOS .icns from the master icon PNG using Apple's iconutil.
+# macOS applies squircle mask + shadow natively from .icns — no manual masking needed.
+set -e
+
+SRC="build/icon.png"
+ICONSET="build/icon.iconset"
+
+mkdir -p "$ICONSET"
+sips -z 16 16     "$SRC" --out "$ICONSET/icon_16x16.png"      >/dev/null
+sips -z 32 32     "$SRC" --out "$ICONSET/icon_16x16@2x.png"   >/dev/null
+sips -z 32 32     "$SRC" --out "$ICONSET/icon_32x32.png"      >/dev/null
+sips -z 64 64     "$SRC" --out "$ICONSET/icon_32x32@2x.png"   >/dev/null
+sips -z 128 128   "$SRC" --out "$ICONSET/icon_128x128.png"    >/dev/null
+sips -z 256 256   "$SRC" --out "$ICONSET/icon_128x128@2x.png" >/dev/null
+sips -z 256 256   "$SRC" --out "$ICONSET/icon_256x256.png"    >/dev/null
+sips -z 512 512   "$SRC" --out "$ICONSET/icon_256x256@2x.png" >/dev/null
+sips -z 512 512   "$SRC" --out "$ICONSET/icon_512x512.png"    >/dev/null
+sips -z 1024 1024 "$SRC" --out "$ICONSET/icon_512x512@2x.png" >/dev/null
+
+iconutil -c icns "$ICONSET" -o build/icon.icns
+rm -rf "$ICONSET"

packages/desktop/src/main.ts

@@ -513,16 +513,6 @@ if (!gotTheLock) {
   // ─── App Lifecycle ──────────────────────────────────────────────────────────
 
   app.whenReady().then(async () => {
-    // Set dock icon on macOS (overrides default Electron icon in dev mode)
-    if (process.platform === 'darwin' && app.dock) {
-      const dockIcon = path.join(__dirname, '..', 'build', 'icon-dock.png');
-      const fallbackIcon = path.join(__dirname, '..', 'build', 'icon.png');
-      const iconPath = fs.existsSync(dockIcon) ? dockIcon : fallbackIcon;
-      if (fs.existsSync(iconPath)) {
-        app.dock.setIcon(iconPath);
-      }
-    }
-
     // macOS application menu with "Change Instance"
     if (process.platform === 'darwin') {
       const appMenu = Menu.buildFromTemplate([