Phase 5 Stage E: full kind migration into packages/nodes

Wholesale move of every remaining kind into its own subdirectory under
`packages/nodes/src/`, finishing the registry-driven migration. Each
kind now ships its definition, schema (re-exported from core), and any
of `geometry` / `renderer` / `system` / `floorplan` / `tool` /
`move-tool` / `panel` / `floorplan-move` / `floorplan-affordances` /
`parametrics` / `preview` it needs — no per-kind code remains under
`packages/editor/src/components/tools/` or
`packages/viewer/src/components/renderers/`.

Deleted (replaced by registry-driven equivalents):
- `tools/{ceiling,column,door,fence,item,slab,spawn,wall,window}/...`
  (boundary editors, hole editors, placement tools, move tools,
  endpoint movers, curve tools, helpers, math libs)
- `ui/helpers/{ceiling,slab,wall}-helper.tsx`
- `ui/panels/{column,door,elevator,item,roof,roof-segment,spawn,
  stair,stair-segment,wall,window}-panel.tsx`
- `viewer/src/components/renderers/{building,ceiling,column,door,
  elevator,fence,guide,item,level,roof,roof-segment,scan,site,slab,
  spawn,stair,stair-segment,wall,window,zone}-renderer.tsx`
- `viewer/src/components/viewer/legacy-system.tsx`

Added under `packages/nodes/src/`:
- `building/`, `column/`, `elevator/`, `guide/`, `level/`, `roof/`,
  `roof-segment/`, `scan/`, `shared/`, `site/`, `stair/`,
  `stair-segment/` packages with definition + schema + renderer / system
  / floorplan / panel as appropriate.
- New `floorplan-move.ts` for every kind that supports 2D moves
  (ceiling, door, item, shelf, slab, window) — single registry-driven
  dispatch path via `def.floorplanMoveTarget`.
- New `floorplan-affordances.ts` for kinds with polygon / endpoint
  drags (ceiling, fence, slab, wall) — using the shared
  `polygon-vertex-affordance` factories.
- New per-kind `panel.tsx` for kinds with custom inspector content
  (door, item, shelf, spawn, wall, window).
- New per-kind `tool.tsx` for placement (door, item, shelf, window).
- New per-kind `move-tool.tsx` for kinds with custom 3D move flows
  (door, item, slab, window).

Coordinator + manager updates in `packages/editor/`:
- `tool-manager.tsx` resolves tools from the registry only — no
  hardcoded type→component map.
- `panel-manager.tsx` resolves inspector panels the same way.
- `placement-{coordinator,strategies,types}.ts` extended with
  shelf-surface placement.
- `selection-manager.tsx` adds the registry-selectable fallback.
- `floorplan-panel.tsx`, `floorplan-background-placement.ts`,
  `floorplan-render-context.tsx` updated for the registry layer's new
  contract (props, affordance dispatch, render context).

Viewer updates:
- `viewer/index.tsx` drops legacy renderer mounts.
- `node-renderer.tsx` resolves by registry only.
- `scene-bvh.tsx`, `use-node-events.ts`, `level-system.tsx`,
  `wall-cutout.tsx`, `zone-system.tsx`, `materials.ts` adjusted for
  the registry-only world.

Sidebar tree nodes for ceiling / fence / slab / shelf / tree-node
updated to read from the registered nodes instead of the deleted
legacy renderer trees.

Wiki: new `plugin-authoring.md` page, README index updated.

Tests in `packages/nodes/src/index.test.ts` validate every registered
kind has the required shape.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/nodes/src/door/floorplan-move.ts

@@ -0,0 +1,87 @@
+import {
+  type AnyNodeId,
+  type DoorNode,
+  type FloorplanMoveTarget,
+  type FloorplanMoveTargetSession,
+  useScene,
+} from '@pascal-app/core'
+import { snapToHalf } from '@pascal-app/editor'
+import { findClosestWallInPlan } from '../shared/wall-attach-target'
+import { clampToWall, hasWallChildOverlap } from './door-math'
+
+/**
+ * 2D floor-plan move handler for door — kicks in when the user clicks
+ * "Move" on the door inspector (or action menu) and the floor-plan
+ * view is active. Pointer in plan space → snap to nearest wall →
+ * project onto wall axis → snap local-X to 0.5m grid → clamp inside
+ * wall bounds → commit via `useScene.updateNodes`.
+ *
+ * Mirrors the 3D `move-tool.tsx` behaviour minus the R3F event plumbing:
+ *   - Re-parents on transition between walls (parentId + wallId).
+ *   - Adapts `side` + `rotation` from the wall normal under the pointer.
+ *   - hasWallChildOverlap blocks committing overlapping placements.
+ *
+ * Curved walls are skipped by `findClosestWallInPlan` — same guardrail
+ * as the 3D port and the legacy `DoorTool` / `MoveDoorTool`.
+ */
+
+export const doorFloorplanMoveTarget: FloorplanMoveTarget<DoorNode> = ({ node }) => {
+  // Snapshot of the door's "valid" state at move-start — used by
+  // canCommit to decide whether the current snapped position is OK.
+  const startLevelId = (() => {
+    // Walk up via parentId until we hit a node whose type isn't 'wall'
+    // — that's the level (or null). The door is wall-hosted, so the
+    // wall's parent is the level. Cached at start because the parent
+    // chain doesn't change during a move.
+    const wall = useScene.getState().nodes[node.parentId as AnyNodeId]
+    return wall ? (wall.parentId as AnyNodeId | null) : null
+  })()
+
+  const session: FloorplanMoveTargetSession = {
+    affectedIds: [node.id as AnyNodeId],
+    apply({ planPoint, modifiers }) {
+      const nodes = useScene.getState().nodes
+      const hit = findClosestWallInPlan(planPoint, nodes, startLevelId)
+      if (!hit) return // pointer off any wall — keep door at last valid position
+
+      // Snap the wall-local X to 0.5m grid (Shift bypasses).
+      const snappedLocalX = modifiers.shiftKey ? hit.localX : snapToHalf(hit.localX)
+      const { clampedX, clampedY } = clampToWall(hit.wall, snappedLocalX, node.width, node.height)
+
+      // Build the updates atomically — position + rotation + side +
+      // parentId + wallId in a single scene write. The current door's
+      // parent might be a different wall; re-anchoring requires moving
+      // the node in the parent's children list (the registry's
+      // updateNode does this when parentId changes).
+      useScene.getState().updateNodes([
+        {
+          id: node.id as AnyNodeId,
+          data: {
+            position: [clampedX, clampedY, 0],
+            rotation: [0, hit.itemRotation, 0],
+            side: hit.side,
+            parentId: hit.wall.id,
+            wallId: hit.wall.id,
+          },
+        },
+      ])
+    },
+    canCommit() {
+      const live = useScene.getState().nodes[node.id as AnyNodeId] as DoorNode | undefined
+      if (!live || live.type !== 'door') return false
+      // Block commit if the door overlaps any other wall child at its
+      // current position. The 3D port has the same guard.
+      const overlapping = hasWallChildOverlap(
+        live.parentId as string,
+        live.position[0],
+        live.position[1],
+        live.width,
+        live.height,
+        live.id,
+      )
+      return !overlapping
+    },
+  }
+
+  return session
+}