fix(web): carry the merged master through the add-workspace helper

Master gained a web-search e2e scenario that calls connectFreshWorkspace
with the pre-change one-argument signature, which fails to compile against
the test-merge commit CI builds. Give it the scaffold's workspace root like
every other scenario.

Master also gained the first-run welcome notice. The shared scaffold
acknowledges it before boot, but the W5 smoke spawns its own server against
a fresh $DSH_HOME, so its overlay owns pointer events and swallows the
first click on the workspace chip; the scenario now dismisses the notice
first. The notice is anchored structurally because this spec belongs to the
client TypeScript program, which does not reference the package owning its
copy.

apps/web/tests/web-search-round.e2e.ts

@@ -109,7 +109,7 @@ describe('web e2e: shipped default web search', () => {
     tripwire = watchConsole(page)
     await page.goto(scaffold.baseUrl, { waitUntil: 'load' })
     await page.waitForSelector('[class*="frame"]', { timeout: 30_000 })
-    await connectFreshWorkspace(page)
+    await connectFreshWorkspace(page, scaffold.workspaceCwd)
   }, 120_000)
 
   afterAll(async () => {