Self-contained desktop dev script with worktree isolation

dev:desktop now launches its own Metro on a random port + Electron,
no dependency on a shared :8081. In worktrees, Electron gets a unique
userData path and dock badge so multiple instances run side-by-side.

packages/desktop/package.json

@@ -7,7 +7,7 @@
   "scripts": {
     "build": "npm --prefix ../.. run build:daemon && npm run build:main && electron-builder --config electron-builder.yml",
     "build:main": "tsc -p tsconfig.json",
-    "dev": "npm run build:main && wait-on tcp:8081 && electron .",
+    "dev": "./scripts/dev.sh",
     "test": "vitest run",
     "typecheck": "tsc --noEmit -p tsconfig.json"
   },

packages/desktop/scripts/dev.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+DESKTOP_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"
+APP_DIR="$(cd "$DESKTOP_DIR/../app" && pwd)"
+ROOT_DIR="$(cd "$DESKTOP_DIR/../.." && pwd)"
+
+# Build the Electron main process
+npm run build:main
+
+# Get a random available port for Metro
+EXPO_PORT=$("$ROOT_DIR/node_modules/.bin/get-port")
+export EXPO_PORT
+
+echo "══════════════════════════════════════════════════════"
+echo "  Paseo Desktop Dev"
+echo "══════════════════════════════════════════════════════"
+echo "  Metro:     http://localhost:${EXPO_PORT}"
+echo "══════════════════════════════════════════════════════"
+
+# Launch Metro + Electron together, kill both on exit
+"$ROOT_DIR/node_modules/.bin/concurrently" \
+  --kill-others \
+  --names "metro,electron" \
+  --prefix-colors "magenta,cyan" \
+  "cd '$APP_DIR' && npx expo start --port $EXPO_PORT" \
+  "$ROOT_DIR/node_modules/.bin/wait-on tcp:$EXPO_PORT && EXPO_DEV_URL=http://localhost:$EXPO_PORT electron '$DESKTOP_DIR'"

packages/desktop/src/main.ts

@@ -8,6 +8,7 @@ inheritLoginShellEnv();
 import path from "node:path";
 import { pathToFileURL } from "node:url";
 import { existsSync } from "node:fs";
+import { execFileSync } from "node:child_process";
 import { app, BrowserWindow, ipcMain, nativeImage, net, protocol } from "electron";
 import { registerDaemonManager } from "./daemon/daemon-manager.js";
 import {
@@ -38,6 +39,37 @@ const APP_SCHEME = "paseo";
 const OPEN_PROJECT_EVENT = "paseo:event:open-project";
 app.setName("Paseo");
 
+// In dev mode, detect git worktrees and isolate each instance so multiple
+// Electron windows can run side-by-side (separate userData = separate lock).
+let devWorktreeName: string | null = null;
+if (!app.isPackaged) {
+  try {
+    const topLevel = execFileSync("git", ["rev-parse", "--show-toplevel"], {
+      encoding: "utf-8",
+      timeout: 3000,
+    }).trim();
+    devWorktreeName = path.basename(topLevel);
+    // Main checkout (e.g. "paseo") gets default userData — only worktrees diverge.
+    const commonDir = path.resolve(
+      topLevel,
+      execFileSync("git", ["rev-parse", "--git-common-dir"], {
+        cwd: topLevel,
+        encoding: "utf-8",
+        timeout: 3000,
+      }).trim(),
+    );
+    const isWorktree = path.resolve(topLevel, ".git") !== commonDir;
+    if (isWorktree) {
+      app.setPath("userData", path.join(app.getPath("appData"), `Paseo-${devWorktreeName}`));
+      log.info("[worktree] isolated userData for worktree:", devWorktreeName);
+    } else {
+      devWorktreeName = null;
+    }
+  } catch {
+    devWorktreeName = null;
+  }
+}
+
 // Allow users to pass Chromium flags via PASEO_ELECTRON_FLAGS for debugging
 // rendering issues (e.g. "--disable-gpu --ozone-platform=x11").
 // Must run before app.whenReady().
@@ -127,7 +159,9 @@ async function createMainWindow(): Promise<void> {
   const iconPath = getWindowIconPath();
   const systemTheme = resolveSystemWindowTheme();
 
+  const title = devWorktreeName ? `Paseo (${devWorktreeName})` : "Paseo";
   const mainWindow = new BrowserWindow({
+    title,
     width: 1200,
     height: 800,
     show: false,
@@ -144,6 +178,10 @@ async function createMainWindow(): Promise<void> {
     },
   });
 
+  if (devWorktreeName) {
+    app.dock?.setBadge(devWorktreeName);
+  }
+
   setupWindowResizeEvents(mainWindow);
   setupDefaultContextMenu(mainWindow);
   setupDragDropPrevention(mainWindow);