- components/plan-block.tsx: hand-built SVG (user decision) — deterministic
layered layout (Kahn topo + longest-path depth, rows centered, authoring
tie-break), bezier edges, the retired panel's status color language.
- PlanBlock renders data-plan-block parts AS CARRIED (frozen snapshots,
never re-derived): kind full = borderless, viewBox = layout extent so
nodes hug the column edges, natural height; kind neighborhood = own
small labeled 'Plan fragment' container with the current node glowing
(pulsing primary halo).
- PlanPopup: full-screen overlay with the LIVE plan — latest tree from the
transcript, statuses derived at click time via derivePlanStatuses
(contracts/plan.ts). Esc / backdrop / X close; drag pan, wheel
zoom-to-cursor, zoom buttons; fit-floor semantics harvested from the
retired tree panel (zoom floor = the fit, pan locks at it).
- chat.tsx: data-plan-block case in the part switch + popup mount.
- src/core/ui-message.ts: TeacherUIDataParts gains "plan-block": PlanBlockData
(additive, type-only — lane touch flagged to master).
- tests/render-plan-block.test.tsx: pure layout (layering, centering,
dangling-edge tolerance), wrap, frozen-snapshot render, live derivation.
