The bench timed two of the six RPCs the fix touches. Extend it to
image.attach, pdf.attach, clipboard.paste and image.detach so every changed
handler carries a number rather than an inference.
Also report which surfaces reach these RPCs at all, since "why was the GUI
special" is the first question the fix invites. CLI attaches inline in its
own turn path with the agent already built, so it cannot reach the stall;
the TUI calls the same RPCs and was equally exposed. The difference was hit
rate, not code path.
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