[wingleeio]

Selecting a streaming reply could lose its drag anchor when automatic tail-following moved the row out of the virtual list before the first mouse move. Selection now takes control of the viewport immediately while preserving the runway, edge scrolling, and the ability to return to the live tail.

Expanding a user prompt could also permanently consume the runway. Show more and Show less now adjust the reservation with the prompt's height animation, so only reply growth consumes it. Jumping beneath an expanded prompt still reaches the reply.

The macOS redraw freeze is addressed by a pinned GPUI backend fix: a stopped or failed frame source no longer leaves its request flag latched, and sources reconnect on system/display wake and session activation. This matches the reported symptom of messages sending while the display stays frozen; the original hardware incident has not been reproduced. Idle parking and display-paced rendering remain enabled. Investigation and hardware follow-up.

Validation:

• All 620 release UI tests pass, including new regressions for selection during a stream burst, selection through completion, and prompt expansion/collapse followed by real overflow. Both reported regressions failed before their fixes.
• macOS checks pass: application compile check and native frame-source regression with two injected CoreVideo start failures, verifying that each allows another restart attempt. Physical sleep/wake reproduction remains unverified.
• Existing runway, wheel scrolling, resize, completion, and viewport-restoration tests pass. Native release build succeeds.
• Two native Linux/X11 adapter replays completed successfully; no model API calls. Validation and reproduction details.

Video proof:
Show more / Show less preserve the runway during streaming (43s):

show-more-runway.mp4

Select live overflowing output, then resume tail scrolling (38s):

live-selection.mp4

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