fix(ci): exercise production WorkHub browser click path

[Sun-GLiang]

Summary

After Main closes, the WorkHub browser smoke manually dispatches a mouse down/up pair. That skips the target scrolling, hit testing and pointer positioning used by the production OpenCLI path.

Use withBrowserPage for navigation and page.click, assert click_method === 'cdp', and keep the observed “Clicked” effect assertion. Release the acquired browser session in finally.

Preserve main's bounded two-frame readiness wait inside the click action lease so the background page stays active until the single native click. Main's color-managed screen capture checks are also retained.

Split from #5969 following its scope review. This changes only the smoke script.

Verification

• Root build, typecheck, lint, format and desktop/UI Knip checks pass locally on Node 24.
• After merging main (16a8f5b84), all 56 browser-session, browser-IPC, browser-view-manager and WorkHub-presentation tests pass locally.
• The native WorkHub browser presentation smoke passes on macOS, including all screen-pixel assertions and the production CDP click after Main closes. Main's color-managed capture fix resolves the earlier local screenshot failure.
• Linux/Xvfb native smoke verification remains required in CI.

AI use

• No generative tool made a substantive contribution
• Generative tooling made a substantive contribution

Tool(s) and scope: Codex (GPT-6) authored the smoke change, resolved the main-branch conflict, and updated this description. The affected commits retain Generated-by: Codex (GPT-6).

Checklist

• Existing native-input and observed-click assertions are retained
• Build, lint, format and typecheck pass locally
• Native smoke passes on the Linux/Xvfb CI environment

Does this PR entail a change in behavior?

• Yes
• No — smoke coverage and teardown only