The composer seat is one node laid out against two different edges: in Chat it
is a sticky child of the column's scroller and rides its content box, which a
space-consuming scrollbar shortens, while a view declaring a composer overlay
gets an absolutely positioned seat against the padding box, which no bar
reduces. With the transcript scrolling the two tabs disagreed by the bar's
width, so the centred input card moved 4px sideways on every switch — and the
same 4px inside Chat when a growing transcript began to scroll.
The column now reserves its scrollbar gutter unconditionally and states the
overlay branch a scroll container on the same axes, so both states measure
against the same width.
Resuming a long session (196k events, 2.2k steps, 1.8k tool cards) took
~12s to render and ~800ms to echo one keystroke:
- Every step's timing footer called stepTimingAt, which replayed the whole
event log per footer - O(steps x events) on the initial render.
- pi-tui re-renders every component each frame and relies on per-component
line caches, but ToolCardComponent/ContextCardComponent built throwaway
Text/Markdown instances inside render(width), re-wrapping every settled
card's output on every keystroke.
Replace the per-footer replay with one shared StepTimingTracker per chat
mount (single O(events) cursor over the append-only log), and cache card
rows by width via CardLineCache, dropped by every state mutator and
invalidate().
Measured (tmux 200x50, 196k-event session): resume prompt-ready ~12s -> ~7.6s;
per-keystroke echo ~800ms median -> ~11ms.
session-title already registers a title projection unit; /resume now
reads it instead of scanning logs: live rows from the registry
snapshot, persisted rows from the durable checkpoint row
(cachedSnapshot, zero I/O), and only rows without a usable checkpoint
pay a coldSnapshot — checkpoint plus readFrom tail, written back so the
next scan is metadata-only. Cold reads are bounded by the new
resumeScanConcurrency config; compositions without the cache fall back
to the bounded readTitleSnapshots batch. The TUI overlay mounts the
projection registry, storage, and projection-cache rows over the same
storages root the web surface uses, so checkpoints serve both.
Derive turn wall time from adjacent logged timestamps (no new session
events): the actions-owning assistant footer gains a localized
"Ran for {duration}" label, and the running TurnStatus label gains a
live elapsed clock anchored to the same logged trigger so a mid-turn
reload keeps the real elapsed time. Message time chrome is now
hover-revealed on hover-capable devices, keeping icons visible and
layout stable.
Making `.sources` a scroll container turned its `padding-left` from spacing
into a correctness constraint. A scroll container clips inline-start overflow
with no way to scroll it back, and `::marker` is right-aligned to the content
edge, so past nine sources the markers rendered as `0.` and `1.` where `10.`
and `11.` belonged.
`searchMaxResults` is an unbounded positive integer, so size the padding in
`em` against the list's own font to hold a three-digit marker. The browser e2e
measures a `999. ` marker in that inherited font and requires the computed
padding to be at least that wide, pinning the room against the widest marker
rather than one fixture's source count.
