Two concerns in one commit (separate files, each self-contained):
## Canvas.tsx split (from ~680 to ~250 lines)
Canvas.tsx was holding drag gesture state + keyboard shortcuts +
viewport wiring + JSX. Each concern now lives in its own unit under
canvas/src/components/canvas/:
- dragUtils.ts — pure: shouldDetach, clampChildIntoParent,
DETACH_FRACTION
- DropTargetBadge.tsx — the floating "Drop into: <name>" label + the
dashed ghost preview at the target slot
- useDragHandlers.ts — encapsulates onNodeDragStart / Drag / Stop,
findDropTarget hit-test, pendingNest state,
and confirmNest/cancelNest. Routes multi-
select drags through batchNest automatically.
- useKeyboardShortcuts — Esc, Enter, Shift+Enter, Cmd+]/[, Z — one
window listener, one source of truth.
- useCanvasViewport — pan-to-node + zoom-to-team CustomEvent
listeners and the debounced viewport save.
Canvas.tsx becomes a thin composition + JSX file. No behavioural
change; the refactor is covered by the existing 915 canvas tests.
## batchNest parallelization (2N round-trips → N, all in flight)
Previously nestNode fired two sequential PATCHes (parent_id then x/y)
and batchNest looped nestNode sequentially. For a 5-node selection on
a typical ~200ms link this was ~2s of serialized RPCs.
- nestNode now combines parent_id + x + y into ONE PATCH. The Go
handler (workspace_crud.go Update) already reads all three from the
same body — no backend change.
- batchNest rewritten: compute every re-parent plan against one
snapshot, commit a single set(), then fire N PATCHes via
Promise.allSettled in parallel. Per-node failures roll back only
that node (others stay committed) — same semantics as the single-
node path, just concurrent.
- The state math in the batch path also correctly shifts descendant
zIndex by depthDelta when any re-parented node has a subtree.
## Also
- canvas-topology.ts: reverted P3.12's opt-in rescue to the auto-
rescue default. When a child's stored relative position would render
it outside the parent bbox (the visual regression the user saw after
collapse → reload — Hermes child drawn outside Claude Code Agent on
first paint), the child is placed in the next default grid slot.
The "Arrange Children" context command stays for bigger teams.
All 915 canvas tests pass. No backend changes.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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