- Clear bed: a "Clear (N)" action on a focused plantable object → confirm modal
  (ClearBedModal) → soft-removes every active plop (useClearObject loops PATCHes,
  invalidates once); rows kept with removed_at.
- Keyboard nudging (desktop): arrows move the selected object/plop 1cm, Shift
  10cm; the PATCH is debounced ~400ms on key-idle. Plops nudge in the object's
  local frame and clamp to its bounds; ignored while typing in a field.
- Empty states: hint to place a first bed on an empty field, and to add a plant
  in an empty focused bed (both non-interactive overlays).
- Paper cuts: per-route document titles (usePageTitle on every page), an emoji
  favicon, and a 404 catch-all route (NotFound) inside the app shell.
- Mobile: plop tap targets stay ≥~44px at low zoom via a transparent hit circle.
- Ownership check hoisted to the authoritative ownerId==me so the nudge handler
  can gate on canEdit before the loading early-returns.

Imperial coverage verified across inspectors/forms/cards/picker (all via the
unit-aware helpers); conversion helpers stay in lib/units.ts (their home since #8).

tsc --noEmit clean; 24/24 vitest; production build green.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01JdQpdYYsTgtkJBxbcpAszi

@@ -0,0 +12,4 @@
+      </p>
+      <h1 className="text-lg font-semibold text-fg">Page not found</h1>
+      <p className="text-sm text-muted">That page doesn't exist — the link may be wrong or the page moved.</p>
+      <Link to="/gardens" className={buttonClasses('primary')}>

@@ -0,0 +32,4 @@
+            type="button"
+            variant="danger"
+            disabled={clear.isPending}
+            onClick={() => clear.mutate(plops, { onSuccess: onClose })}

@@ -266,0 +266,4 @@
+/** Clear a bed: soft-remove every active plop in an object (a loop of PATCHes;
+ *  a bulk ClearObject endpoint arrives with the agent seam, #19). Invalidates
+ *  once at the end. Pass the object's active plops (id + current version). */
+export function useClearObject(gardenId: number) {

@@ -266,0 +271,4 @@
+  return useMutation({
+    mutationFn: async (plops: { id: number; version: number }[]) => {
+      const today = new Date().toISOString().slice(0, 10)
+      await Promise.all(

@@ -266,0 +275,4 @@
+        plops.map((p) => api.patch(`/plantings/${p.id}`, { removedAt: today, version: p.version })),
+      )
+    },
+    onSuccess: () => qc.invalidateQueries({ queryKey: fullKey(gardenId) }),

@@ -0,0 +3,4 @@
+/** Set the document title for the current route (suffixed with · pansy), and
+ *  restore the previous title on unmount. */
+export function usePageTitle(title: string): void {
+  useEffect(() => {

@@ -54,0 +60,4 @@
+  // Role gating, computed before the effects/returns so the nudge handler can use
+  // it. Ownership is the authoritative ownerId==me check.
+  const gd = full.data?.garden
+  const canEdit = gd != null && (gd.ownerId === me.data?.id || gd.myRole === 'editor')

@@ -111,0 +123,4 @@
+  // Desktop keyboard nudging: arrows move the selected object/plop 1cm (Shift =
+  // 10cm); the PATCH is debounced ~400ms on key-idle so a held key doesn't spam.
+  // Plops nudge in their object's local frame and clamp to its bounds.
+  useEffect(() => {

@@ -111,0 +131,4 @@
+      ArrowLeft: [-1, 0],
+      ArrowRight: [1, 0],
+    }
+    const commitLater = (fire: () => void) => {

@@ -111,0 +145,4 @@
+      if (el && (el.tagName === 'INPUT' || el.tagName === 'TEXTAREA' || el.tagName === 'SELECT')) return
+      const s = useEditorStore.getState()
+      const step = e.shiftKey ? 10 : 1
+      if (s.selectedId != null) {

@@ -111,0 +151,4 @@
+        e.preventDefault()
+        const next = { ...base, xCm: base.xCm + dir[0] * step, yCm: base.yCm + dir[1] * step }
+        s.setLiveObject(next)
+        commitLater(() => {

@@ -111,0 +165,4 @@
+        const obj = objects.find((o) => o.id === base.objectId)
+        let nx = base.xCm + dir[0] * step
+        let ny = base.yCm + dir[1] * step
+        if (obj) {

@@ -111,0 +180,4 @@
+    window.addEventListener('keydown', onKey)
+    return () => {
+      window.removeEventListener('keydown', onKey)
+      if (nudgeTimer.current != null) window.clearTimeout(nudgeTimer.current)

@@ -190,1 +272,4 @@
         <GardenCanvas garden={garden} objects={objects} plantings={plantings} plantsById={plantsById} canEdit={canEdit} />
+
+        {/* Empty-state hints (non-interactive overlays). */}
+        {canEdit && focusedObjectId == null && objects.length === 0 && (

@@ -232,0 +330,4 @@
+
+      {clearing && focusedObject && (
+        <ClearBedModal
+          objectName={focusedObject.name || kindDef(focusedObject.kind)?.label || 'bed'}