fix(subs): stop the lock/reload on source actions + regroup the row buttons

Lock/reload: every inline source action (check / backfill / recover / toggle /
remove) ended by refetching the WHOLE subscription list (store.loadAll /
refresh), which blocked the UI and re-rendered the table — collapsing the
expanded row, which read as "locks then resets." The action APIs already return
the updated source, so the store now patches that one row in place
(_patchSource / _dropSource); the post-action loadAll/refresh calls are gone.
Toggling enabled, starting/stopping a backfill, recovering, and removing are now
instant and leave the expansion intact.

Button regroup (operator-flagged: tiny, mis-clickable, not grouped by function):
- New shared SourceActions.vue used by desktop SourceRow + mobile SourceCard.
- Frequent actions stay as size="small" buttons: Check, Backfill/Stop.
- Low-frequency / destructive actions move into a labelled overflow (⋮) menu —
  Preview backfill, Recover dropped near-duplicates, Remove source — so they
  can't be fat-fingered, and the labels spell out recover-vs-backfill.
- Edit moves next to the source URL (its identity), out of the action cluster
  where it sat beside Remove.
- Single-source Remove now confirms (it had no guard before).

Tests: store patches/drops in place without dropping the cache.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/components/subscriptions/SourceCard.vue

@@ -12,10 +12,19 @@
       />
     </div>
 
-    <a
-      :href="source.url" target="_blank" rel="noopener"
-      class="fc-source-card__url" @click.stop
-    >{{ source.url }}</a>
+    <div class="fc-source-card__url-row">
+      <a
+        :href="source.url" target="_blank" rel="noopener"
+        class="fc-source-card__url" @click.stop
+      >{{ source.url }}</a>
+      <v-btn
+        icon="mdi-pencil" size="x-small" variant="text"
+        @click.stop="$emit('edit', source)"
+      >
+        <v-icon>mdi-pencil</v-icon>
+        <v-tooltip activator="parent" location="top">Edit source</v-tooltip>
+      </v-btn>
+    </div>
 
     <div class="fc-source-card__meta">
       <span>Last {{ formatRelative(source.last_checked_at) }}</span>
@@ -42,61 +51,20 @@
     </div>
 
     <div class="fc-source-card__actions">
-      <v-btn
-        size="x-small" variant="text" :loading="checking"
-        @click.stop="$emit('check', source)"
-      >
-        <v-icon>mdi-play</v-icon>
-        <v-tooltip activator="parent" location="top">Check now</v-tooltip>
-      </v-btn>
-      <v-btn
-        size="x-small" variant="text"
-        :color="source.backfill_state === 'running' ? 'warning' : undefined"
-        @click.stop="$emit('backfill', source)"
-      >
-        <v-icon>{{ source.backfill_state === 'running' ? 'mdi-stop' : 'mdi-magnify-scan' }}</v-icon>
-        <v-tooltip activator="parent" location="top">
-          {{ source.backfill_state === 'running'
-            ? (source.backfill_bypass_seen ? 'Stop recovery' : 'Stop backfill')
-            : 'Backfill full history' }}
-        </v-tooltip>
-      </v-btn>
-      <v-btn
-        v-if="source.platform === 'patreon' && source.backfill_state !== 'running'"
-        size="x-small" variant="text"
-        @click.stop="$emit('preview', source)"
-      >
-        <v-icon>mdi-eye-outline</v-icon>
-        <v-tooltip activator="parent" location="top">
-          Preview — count what a backfill would download (no download)
-        </v-tooltip>
-      </v-btn>
-      <v-btn
-        v-if="source.platform === 'patreon' && source.backfill_state !== 'running'"
-        size="x-small" variant="text"
-        @click.stop="$emit('recover', source)"
-      >
-        <v-icon>mdi-backup-restore</v-icon>
-        <v-tooltip activator="parent" location="top">
-          Recover — re-fetch dropped near-dups &amp; re-evaluate under the current threshold
-        </v-tooltip>
-      </v-btn>
-      <v-btn size="x-small" variant="text" @click.stop="$emit('edit', source)">
-        <v-icon>mdi-pencil</v-icon>
-        <v-tooltip activator="parent" location="top">Edit</v-tooltip>
-      </v-btn>
-      <v-btn
-        size="x-small" variant="text" color="error"
-        @click.stop="$emit('remove', source)"
-      >
-        <v-icon>mdi-close</v-icon>
-        <v-tooltip activator="parent" location="top">Remove</v-tooltip>
-      </v-btn>
+      <SourceActions
+        :source="source" :checking="checking"
+        @check="$emit('check', $event)"
+        @backfill="$emit('backfill', $event)"
+        @recover="$emit('recover', $event)"
+        @preview="$emit('preview', $event)"
+        @remove="$emit('remove', $event)"
+      />
     </div>
   </div>
 </template>
 
 <script setup>
+import SourceActions from './SourceActions.vue'
 import SourceHealthDot from './SourceHealthDot.vue'
 import { formatRelative } from '../../utils/date.js'
 
@@ -124,11 +92,15 @@ function onToggleEnabled(value) {
   display: flex; flex-direction: column; gap: 6px;
 }
 .fc-source-card__top { display: flex; align-items: center; gap: 8px; }
+.fc-source-card__url-row {
+  display: flex; align-items: center; gap: 4px;
+}
 .fc-source-card__url {
   color: rgb(var(--v-theme-on-surface-variant));
   text-decoration: none;
   font-size: 0.8rem;
   word-break: break-all;
+  flex: 1 1 auto; min-width: 0;
 }
 .fc-source-card__url:hover { color: rgb(var(--v-theme-accent)); }
 .fc-source-card__meta {