Coalesce redraws to fix 100% CPU from full-screen agent TUIs#49
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Full-screen agent TUIs (notably OpenCode) repaint continuously with byte-identical frames and never go output-quiet, which pinned the render loop at its 60 fps frame cap and burned a full core even when idle. Two feedback paths forced this: - Every SessionBytes chunk flagged a redraw via the blanket needs_redraw at the end of handle_event. - The PTY reader emits a SessionCurrentLine heartbeat every ~20ms per session, each also flagging a redraw. Gate both on real change, keyed on rendered content rather than session type so Claude/Codex benefit identically: - process_bytes hashes contents_formatted() and reports whether the visible frame changed; handle_session_bytes redraws only when a *visible* session's screen changed. - handle_session_current_line redraws only when state inference flips the session (its text is already carried by the vt100 screen). State inference on the line path is untouched, so Waiting/Error detection is unchanged for all agents. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Full-screen agent TUIs (notably OpenCode) repaint continuously with byte-identical frames and never go output-quiet, which pinned the render loop at its 60 fps frame cap and burned a full core even when idle.
Two feedback paths forced this:
Gate both on real change, keyed on rendered content rather than session type so Claude/Codex benefit identically:
State inference on the line path is untouched, so Waiting/Error detection is unchanged for all agents.