Remove the per-row delete button from Explore's cards

Matches KanbanCard, which never had one -- deleting a card lives on
its own view now (CardManageMenu's "Delete card"), reachable by
clicking through from either list.

Cleaned up what that leaves unused: the cards store's remove() (its
only caller), and .card-row__delete's styling.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/views/ProjectExploreView.vue

@@ -24,17 +24,6 @@ const sortedCards = computed(() =>
   [...cards.cards].sort((a, b) => a.text.localeCompare(b.text, undefined, { sensitivity: 'base' })),
 )
 
-/** Run a store mutation, surfacing failures and resyncing from the server. */
-async function run(op: Promise<unknown>) {
-  actionError.value = null
-  try {
-    await op
-  } catch (e) {
-    actionError.value = e instanceof ApiError ? e.message : 'Something went wrong.'
-    if (cards.projectId !== null) await cards.load(cards.projectId)
-  }
-}
-
 async function onCreate() {
   submitting.value = true
   actionError.value = null
@@ -58,12 +47,7 @@ async function onCreate() {
     <p v-if="cards.loading && !cards.loaded" class="muted">Loading…</p>
 
     <ul v-else-if="sortedCards.length" class="cards">
-      <CardRow
-        v-for="card in sortedCards"
-        :key="card.id"
-        :card="card"
-        @delete="run(cards.remove(card))"
-      />
+      <CardRow v-for="card in sortedCards" :key="card.id" :card="card" />
     </ul>
 
     <form class="kanban__new form--new-card" @submit.prevent="onCreate">