Fix IPC sender validation error when toggling the Agentic UI feature flag

[bcotrim]

Related issues

• N/A

How AI was used in this PR

Claude Code traced the console error to its root cause and authored the fix; the change was reviewed and verified locally (lint, typecheck, unit tests).

Proposed Changes

Toggling the "Enable Agentic UI" feature flag logged a Failed IPC sender validation check error (surfacing as Error occurred in handler for 'getAppGlobals') on every toggle.

When a UI-mode flag flips, the main window reloads into the other renderer and the allowed IPC origin switches immediately — but we also sent refresh-app-globals to the outgoing renderer, whose resulting getAppGlobals call then failed sender validation. The refresh is pointless for a page that's being replaced (the new renderer fetches fresh globals on boot), so we now skip it when the toggle triggers a renderer reload. Other feature-flag toggles still refresh app globals as before.

The error was benign (it came from the renderer being torn down), so this is a log-noise fix with no user-facing behavior change beyond cleaner consoles.

Testing Instructions

1. Run npm start.
2. In the app menu, toggle Enable Agentic UI under the feature flags menu.
3. Watch the main process console: before this change it logged Error: Failed IPC sender validation check: http://localhost:5173/ on each toggle; now it doesn't.
4. Confirm the window still swaps between the default and agentic renderers in both directions, and that app globals still refresh when toggling a non-UI-mode flag.

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

🤖 Generated with Claude Code

[wpmobilebot]

📊 Performance Test Results

Comparing c7e5368 vs trunk

app-size

Metric	trunk	c7e5368	Diff	Change
App Size (Mac)	1350.65 MB	1350.65 MB	+0.00 MB	⚪ 0.0%

site-editor

Metric	trunk	c7e5368	Diff	Change
load	1070 ms	1083 ms	+13 ms	⚪ 0.0%

site-startup

Metric	trunk	c7e5368	Diff	Change
siteCreation	7020 ms	6995 ms	25 ms	⚪ 0.0%
siteStartup	2354 ms	2358 ms	+4 ms	⚪ 0.0%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change (<50ms diff)

[katinthehatsite]

Nice, I don't see the error anymore 👍