fix: let an outside write that lands during a discard keep the item

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

frontend/src/lib/itemStore.svelte.ts

@@ -470,9 +470,13 @@ class Entry<V> {
 			if (this.origin === 'draft') {
 				const kept = snapshot(this.value)
 				const keptRow = this.row
+				const editsAtStart = this.edits
 				this.replaceValue(undefined)
 				this.reconcile()
 				await this.settleRows([this.key])
+				// An outside write that arrived while the delete was going is newer than this
+				// discard: it has already put the item back, and its row is the item.
+				if (this.edits !== editsAtStart) return { removed: false }
 				// The row is the item: while its delete has not landed, the item is still there.
 				if (this.rowRefused(this.key)) {
 					// The syncer keeps a failed payload for its page-close flush; that delete would

frontend/src/lib/itemStore.test.ts

@@ -435,6 +435,25 @@ describe('item store: origins', () => {
 		expect(rows.writes).toEqual([{ path: 'u/me/r', value: null }])
 	})
 
+	it('keeps a draft-only item an outside write put back while its delete was going', async () => {
+		const rows = fakeRows()
+		const draft = { ...deployedRes, description: 'only a draft' }
+		const { item } = await open(rows, adapter({ draft }))
+		const gate = deferred()
+		rows.hold(gate.promise)
+		const discarded = item.discard()
+		await settle()
+		// The chat writes the same item while the delete is in flight.
+		const fromChat = { ...draft, description: 'written by the chat' }
+		item.applyExternal(fromChat)
+		gate.resolve()
+
+		expect(await discarded).toEqual({ removed: false })
+		expect(item.removed).toBe(false)
+		expect(item.value).toEqual(fromChat)
+		expect(rows.writes.at(-1)).toEqual({ path: 'u/me/r', value: fromChat })
+	})
+
 	it('keeps a draft-only item whose delete did not land', async () => {
 		const rows = fakeRows()
 		const draft = { ...deployedRes, description: 'only a draft' }