Owner round (2026-10-05), Slice D — the dock mechanics:
- INTENT-GATED FOLD: a ResizeObserver on the scroller's content stamps
the existing 400ms mute whenever the transcript GROWS — growth frames
(a live turn streaming under stick-to-bottom's chase) can never fold
the dock; and a fold now needs the distance AND stick-to-bottom's
isAtBottom agreeing the learner left. Fixes the generation churn
(dock disappearing and reappearing while the agent works). Shrinks
stamp nothing (the fold's own morph must not self-mute re-expand).
- MEASURED HEIGHT CAPS: the question (55dvh) and problem (40vh) areas
now cap at the available column (scroller clientHeight − 2rem,
re-measured on resize) via --dock-max-h — questions stretch to the
top bar with sensible padding and scroll internally only when
genuinely huge.
- The practice dock's statement area carries the 'Problem' eyebrow —
the quiz cards' label row, mirrored (dock and transcript card read
identically).
- The fold's CONTENT fade: a 160ms WAAPI fade/rise on the bar↔form
toggle — no remount, so the question form's state survives; the
shell height morph was already animated.
- PracticeDock (components/practice-dock.tsx): the active problem
replaces the composer — statement (markdown+LaTeX) above, the 'Your
thinking' composer-twin below with the two submit lanes (Nudge =
thinking without a commit; Commit = answer commit; ⌘/Ctrl+Enter
commits). Dictation claims the thinking field.
- Transcript cards (practice-cards.tsx + the artifact registry): the
problem card (compact-expandable statement — the commitment NEVER
renders), the conclude card (outcome + verdict + reveal; the
dismissal synthesis is one muted line), and the user-side thinking
register cards (Your thinking / Your solution).
- view.ts: the problem pose joins the placeholder fork (the ack never
flips the part); practice-thinking markers project as data parts;
problem-dismissed markers project nothing.
- chat.tsx: activeProblemOf drives the dock branch (question > problem
> composer), the esc layering gains the problem rung (below question,
above turn) with its discard confirm + the silent marker route; the
thinking submissions POST through the session's optimistic appends.