Clicking a name filled the entry with "@tell Name, " correctly but parked the
caret at column 0, so the player had to click the chat bar to get behind their
own prefix before typing — which defeats most of the point of the affordance.
Self-inflicted in d32ef388. SetText already places the caret at the end, and I
stacked an explicit "move to the end" on top of it. MoveCaret takes a DELTA, so
int.MaxValue overflowed _caret + delta to negative and the clamp landed at
column 0. The redundant call was not merely redundant; it was the bug.
Removing it is the whole fix. The test now pins CaretPos as well as the text,
and reintroducing the call reproduces the reported symptom exactly (expected
11, actual 0).
Solution builds clean; full hermetic gate green.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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