REST fill/clear on objects; clear-bed becomes one change set (#82)

FillRegion and ClearObject were reachable only through the agent toolbox, so
on an instance with no model configured the most valuable bulk operation in a
garden planner — and the one carrying the most carefully reasoned geometry in
the codebase — did not exist at all. internal/service/ops.go said these lived
on *Service so "any future REST surface" would inherit the ACL checks; this is
that surface.

POST /objects/:id/fill takes a region EITHER by compass name ("all", "ne",
"south half") or as an explicit rect in the object's local frame, and refuses
both-or-neither: silently preferring one would make a client bug look like a
geometry bug. It answers 200 rather than 201 because a fill can legitimately
create nothing (the region is already planted) and there is no single resource
to point a Location at.

POST /objects/:id/clear replaces a client-side loop of PATCHes. That loop
wrote one change set per plop, so clearing a 40-plop bed took 40 presses of
Undo to put back — while the agent's clear_object, for the identical
user-facing action, undid in one click. CLAUDE.md states the rule it violated:
multi-row operations record together so they undo as one unit. Moving it
server-side also removes the partial-failure case the loop had to reconcile.

TestClearObjectIsOneChangeSetAPI pins that: fill a bed, count change sets,
clear it, assert the count rose by exactly one.

DESIGN.md's API block gains the two new routes, and the four it was already
missing: GET/POST/DELETE /gardens/:id/share-link and the unauthenticated
GET /public/gardens/:token. An unauthenticated surface absent from the
architecture doc is the one worth fixing on sight.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01H3zbym8Doka2d7D48maSgZ

web/src/lib/objects.ts

@@ -328,28 +328,24 @@ export function useUpdatePlanting(gardenId: number) {
   })
 }
 
-/** 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). */
+/** Clear a bed: soft-remove every active plop in an object (#82).
+ *
+ *  ONE request, and so ONE change set. This used to be a loop of PATCHes, which
+ *  meant clearing a 40-plop bed wrote 40 change sets and took 40 presses of Undo
+ *  to put back — while the agent's clear_object, for the identical user-facing
+ *  action, undid in a single click. The rule it violated is stated in CLAUDE.md:
+ *  multi-row operations record all their changes together so they undo as one
+ *  unit. Doing it server-side also removes the partial-failure case the old loop
+ *  had to reconcile. */
 export function useClearObject(gardenId: number) {
   const qc = useQueryClient()
   return useMutation({
-    mutationFn: async (plops: { id: number; version: number }[]) => {
-      const today = new Date().toISOString().slice(0, 10)
-      // allSettled, not all: a partial failure still soft-removed some rows
-      // server-side, so we must reconcile the cache rather than roll everything
-      // back. Report how many failed.
-      const results = await Promise.allSettled(
-        plops.map((p) => api.patch(`/plantings/${p.id}`, { removedAt: today, version: p.version })),
-      )
-      const failed = results.filter((r) => r.status === 'rejected').length
-      if (failed > 0) {
-        throw new Error(`${failed} of ${plops.length} plants couldn't be cleared — refresh and try again.`)
-      }
+    mutationFn: async (objectId: number): Promise<number> => {
+      const res = (await api.post(`/objects/${objectId}/clear`, {})) as { cleared?: number }
+      return res?.cleared ?? 0
     },
-    // Reconcile on success OR partial failure, so the cache matches the server.
     onSettled: () => qc.invalidateQueries({ queryKey: fullKey(gardenId) }),
-    onError: (err) => toast.error(err instanceof Error ? err.message : 'Could not clear the bed.'),
+    onError: (err) => toast.error(objectErrorMessage(err, 'Could not clear the bed.')),
   })
 }