[DevTools] Fix crash on reorder operation mismatch

[shash-hq]

Debugged a crash where Store throws "Children cannot be added or removed..." during a reorder op.

It seems to happen when the frontend and backend get out of sync regarding the children list (e.g. duplicate keys).

This PR adds a guard in onBridgeOperations. If the operation implies a child count that mismatches the store's state, it now warns and safely skips the operation instructions instead of blowing up the whole DevTools UI.

Added a regression test case to verify the bailout logic.

Fixes #35360

[eps1lon]

Appreciate the attempt to fix these. Usually these are legit bugs in the DevTools reconciler so we can't just safely skip over it every time.

Do you have a reproduction for the bug you're seeing?

[shash-hq]

Ya that makes sense. I went with the defensive approach to keep the DevTools UI from crashing entirely, but I agree it hides the underlying desync.

I don't have a standalone app reproduction yet. I reproduced the crash by writing the regression test which is included in this PR (which manually feeds a mismatched child count to the store).

The original issue points to duplicate keys causing the backend to send these invalid operations. Would you prefer I look into filtering those out on the backend before they are sent, or is a full reproduction app required first?