feat(desktop): optimize cold development startup

package.json

@@ -15,6 +15,7 @@
     "dev:stats": "bun sst shell --stage=production -- bun run --cwd packages/stats/app dev",
     "dev:www": "bun run --cwd packages/www dev",
     "dev:storybook": "bun --cwd packages/storybook storybook",
+    "bench:devex": "bun run --cwd packages/app test:bench:devex",
     "lint": "oxlint",
     "lint:effect-patterns": "ast-grep scan -c script/ast-grep/sgconfig.yml packages/util/src packages/core/src packages/server/src packages/protocol/src packages/cli/src",
     "test:lint-rules": "ast-grep test -c script/ast-grep/sgconfig.yml",

packages/app/e2e/performance/README.md

@@ -2,12 +2,34 @@
 
 The app's high-volume performance diagnostics live under `packages/app/e2e/performance` and are excluded from normal local and CI Playwright discovery. The benchmark config builds the app and serves the production bundle before running scenarios serially.
 
+The `devex` category is the explicit exception to the production-build rule. It measures development commands from submission through a user-visible ready state and has its own Playwright configuration.
+
 Run the suite explicitly from `packages/app`:
 
 ```sh
 bun run test:bench
 ```
 
+Run the desktop development startup benchmark from the repository root:
+
+```sh
+bun run bench:devex
+```
+
+It runs five serial samples of the exact `bun dev:desktop` command. Each sample uses a fresh desktop profile, database, service configuration, service registration, and service process; the desktop selects an isolated ephemeral loopback endpoint. It removes desktop build output and the desktop Vite cache before every run; dependencies, Bun's package cache, and Electron remain installed. The harness stops only that sample's service; it does not stop or change the elected global OpenCode service. The measured endpoint is a visible Home page whose empty-state controls pass Playwright actionability checks. The command's Electron installation check remains inside the measured interval.
+
+Set `DESKTOP_STARTUP_RUNS` only for focused diagnostics:
+
+```sh
+DESKTOP_STARTUP_RUNS=1 bun run bench:devex
+```
+
+Set `OPENCODE_PERFORMANCE_TRACE_DIR` to capture the renderer's CDP trace from attachment through actionable Home:
+
+```sh
+DESKTOP_STARTUP_RUNS=1 OPENCODE_PERFORMANCE_TRACE_DIR=/tmp/opencode-desktop-traces bun run bench:devex
+```
+
 PowerShell:
 
 ```powershell

packages/app/e2e/performance/chrome-trace.ts

@@ -18,9 +18,9 @@ const categories = [
   "disabled-by-default-v8.cpu_profiler",
 ]
 
-export async function startChromeTrace(page: Page, name: string) {
+export async function startChromeTrace(page: Page, name: string): Promise<undefined | (() => Promise<string>)> {
   const directory = process.env.OPENCODE_PERFORMANCE_TRACE_DIR
-  if (!directory) return
+  if (!directory) return undefined
 
   const selectors = process.env.OPENCODE_PERFORMANCE_SELECTOR_TRACE === "1"
   const file = await prepareChromeTrace(directory, name, selectors)

packages/app/e2e/performance/devex/desktop-startup-benchmark.spec.ts

@@ -0,0 +1,26 @@
+import { benchmark } from "../benchmark"
+import {
+  desktopBenchmarkContext,
+  runDesktopStartup,
+  summarizeDesktopStartup,
+  type DesktopStartupSample,
+} from "./desktop-startup"
+
+benchmark.describe("devex: desktop startup", () => {
+  benchmark("opens a cold desktop on Home", async ({ report }, testInfo) => {
+    benchmark.setTimeout(15 * 60_000)
+    const runs = Number(process.env.DESKTOP_STARTUP_RUNS ?? 5)
+    if (!Number.isSafeInteger(runs) || runs < 1) throw new Error("DESKTOP_STARTUP_RUNS must be a positive integer")
+
+    const samples: DesktopStartupSample[] = []
+    const context = await desktopBenchmarkContext(runs)
+    for (let run = 1; run <= runs; run++) {
+      const sample = await runDesktopStartup(run, testInfo).catch((error) => {
+        report(samples.length ? { samples, summary: summarizeDesktopStartup(samples) } : { samples }, context)
+        throw error
+      })
+      samples.push(sample)
+    }
+    report({ samples, summary: summarizeDesktopStartup(samples) }, context)
+  })
+})