refactor(ui): CardHeading primitive for icon+title card/dialog headings (DRY pattern sweep)

The icon+title v-card-title heading (d-flex align-center + gap + <v-icon size=small> +
<span>) was hand-rolled identically in 13 cards/dialogs (15 heading instances).
Consolidate to <CardHeading icon title> (components/common) with an iconColor
prop (error headings) and a default slot for trailing content (spacer+actions,
inline status chip). Adopted everywhere the pattern appears — all-or-nothing per
the hardened DRY process.

Over-DRY guard: plain text-only <v-card-title> one-liners are NOT this pattern
and stay; DownloadDetailModal leads with a status CHIP (not an icon), a different
concept, left alone. §8b: the only remaining d-flex align-center v-card-title is
that intentional variant. Catalog updated.

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

frontend/src/components/settings/BackupCard.vue

@@ -1,9 +1,6 @@
 <template>
   <v-card class="fc-backup-card">
-    <v-card-title class="d-flex align-center" style="gap: 10px;">
-      <v-icon icon="mdi-database-export" size="small" />
-      <span>Backups</span>
-    </v-card-title>
+    <CardHeading icon="mdi-database-export" title="Backups" />
     <v-card-text>
       <p class="fc-muted text-body-2 mb-4">
         pg_dump for the database (fast, nightly-schedulable);
@@ -101,6 +98,7 @@ import { computed, onMounted, onUnmounted, ref } from 'vue'
 
 import { useBackupStore } from '../../stores/backup.js'
 import BackupConfirmModal from '../modal/DestructiveConfirmModal.vue'
+import CardHeading from '../common/CardHeading.vue'
 import BackupRunsTable from './BackupRunsTable.vue'
 
 const store = useBackupStore()

frontend/src/components/settings/BrowserExtensionCard.vue

@@ -1,12 +1,10 @@
 <template>
   <v-card class="fc-ext-card">
-    <v-card-title class="d-flex align-center" style="gap: 10px;">
-      <v-icon icon="mdi-puzzle" size="small" />
-      <span>Browser extension</span>
+    <CardHeading icon="mdi-puzzle" title="Browser extension">
       <span v-if="manifest?.installed" class="text-caption fc-muted">
         · Firefox · v{{ manifest.version }}
       </span>
-    </v-card-title>
+    </CardHeading>
 
     <v-card-text>
       <p class="fc-muted text-body-2">
@@ -112,6 +110,7 @@ import { toast } from '../../utils/toast.js'
 import { computed, onMounted, ref } from 'vue'
 import { useApi } from '../../composables/useApi.js'
 import { copyText } from '../../utils/clipboard.js'
+import CardHeading from '../common/CardHeading.vue'
 
 const api = useApi()
 

frontend/src/components/settings/ImportTaskList.vue

@@ -1,7 +1,6 @@
 <template>
   <v-card>
-    <v-card-title class="d-flex align-center" style="gap: 12px;">
-      <span>Recent import tasks</span>
+    <CardHeading title="Recent import tasks">
       <v-spacer />
       <v-select
         v-model="statusFilter" :items="statusOptions" density="compact"
@@ -29,7 +28,7 @@
       >
         Clear completed…
       </v-btn>
-    </v-card-title>
+    </CardHeading>
     <v-data-table-virtual
       :headers="headers" :items="store.tasks" :loading="store.tasksLoading"
       height="480" density="compact" no-data-text="No tasks yet — trigger a scan above."
@@ -129,6 +128,7 @@ import { toast } from '../../utils/toast.js'
 import { computed, ref } from 'vue'
 import { useImportStore } from '../../stores/import.js'
 import ErrorDetailModal from '../common/ErrorDetailModal.vue'
+import CardHeading from '../common/CardHeading.vue'
 
 const store = useImportStore()
 const statusFilter = ref(null)

frontend/src/components/settings/PostMaintenanceCard.vue

@@ -1,9 +1,6 @@
 <template>
   <v-card class="fc-post-maint">
-    <v-card-title class="d-flex align-center" style="gap: 10px;">
-      <v-icon icon="mdi-post-outline" size="small" />
-      <span>Post maintenance</span>
-    </v-card-title>
+    <CardHeading icon="mdi-post-outline" title="Post maintenance" />
     <v-card-text>
       <p class="fc-muted text-body-2 mb-4">
         Remove <strong>bare posts</strong> — post rows with no images (neither
@@ -61,6 +58,7 @@ import { ref } from 'vue'
 
 import { useAdminStore } from '../../stores/admin.js'
 import SampleNameGrid from '../common/SampleNameGrid.vue'
+import CardHeading from '../common/CardHeading.vue'
 
 const store = useAdminStore()
 const preview = ref(null)

frontend/src/components/settings/SystemActivitySummary.vue

@@ -1,8 +1,6 @@
 <template>
   <v-card class="fc-activity-summary">
-    <v-card-title class="d-flex align-center" style="gap: 10px;">
-      <v-icon icon="mdi-pulse" size="small" />
-      <span>System activity (last min)</span>
+    <CardHeading icon="mdi-pulse" title="System activity (last min)">
       <v-spacer />
       <v-btn
         variant="text" size="small" rounded="pill"
@@ -11,7 +9,7 @@
         View activity
         <v-icon end size="small">mdi-arrow-right</v-icon>
       </v-btn>
-    </v-card-title>
+    </CardHeading>
 
     <v-card-text>
       <v-alert
@@ -36,6 +34,7 @@ import { onMounted, onUnmounted } from 'vue'
 
 import { useSystemActivityStore } from '../../stores/systemActivity.js'
 import QueuesTable from './QueuesTable.vue'
+import CardHeading from '../common/CardHeading.vue'
 
 defineEmits(['open-activity'])
 

frontend/src/components/settings/SystemActivityTab.vue

@@ -2,14 +2,12 @@
   <div class="fc-activity">
     <!-- Queues + workers pane -->
     <v-card class="mb-4">
-      <v-card-title class="d-flex align-center" style="gap: 10px;">
-        <v-icon icon="mdi-pulse" size="small" />
-        <span>Queues + workers</span>
+      <CardHeading icon="mdi-pulse" title="Queues + workers">
         <v-spacer />
         <span class="text-caption fc-muted">
           updated {{ formatRelative(store.queues?.fetched_at) }}
         </span>
-      </v-card-title>
+      </CardHeading>
       <v-card-text>
         <QueuesTable
           :queues="store.queues"
@@ -21,14 +19,12 @@
 
     <!-- Recent failures pane -->
     <v-card class="mb-4">
-      <v-card-title class="d-flex align-center" style="gap: 10px;">
-        <v-icon icon="mdi-alert-circle-outline" size="small" />
-        <span>Recent failures (last 24h)</span>
+      <CardHeading icon="mdi-alert-circle-outline" title="Recent failures (last 24h)">
         <v-spacer />
         <span class="text-caption fc-muted">
           {{ failureCount }} failures
         </span>
-      </v-card-title>
+      </CardHeading>
       <v-card-text>
         <div v-if="errorTypes.length" class="mb-3 fc-pills">
           <v-chip
@@ -79,9 +75,7 @@
 
     <!-- All activity pane -->
     <v-card>
-      <v-card-title class="d-flex align-center" style="gap: 10px;">
-        <v-icon icon="mdi-format-list-bulleted" size="small" />
-        <span>All recent activity</span>
+      <CardHeading icon="mdi-format-list-bulleted" title="All recent activity">
         <v-spacer />
         <v-select
           v-model="filterQueue"
@@ -102,7 +96,7 @@
           <v-icon start size="small">mdi-refresh</v-icon>
           Refresh
         </v-btn>
-      </v-card-title>
+      </CardHeading>
       <v-card-text>
         <v-table density="compact">
           <thead>
@@ -157,6 +151,7 @@ import { useSystemActivityStore } from '../../stores/systemActivity.js'
 import { formatRelative as fmtRelative } from '../../utils/date.js'
 import ErrorDetailModal from '../common/ErrorDetailModal.vue'
 import QueuesTable from './QueuesTable.vue'
+import CardHeading from '../common/CardHeading.vue'
 
 // Click-to-open modal for full error text. Replaces the unusable
 // :title="..." tooltip (operator-flagged 2026-05-26: SQLAlchemy

frontend/src/components/settings/TagMaintenanceCard.vue

@@ -1,9 +1,6 @@
 <template>
   <v-card class="fc-tag-maint">
-    <v-card-title class="d-flex align-center" style="gap: 10px;">
-      <v-icon icon="mdi-tag-remove" size="small" />
-      <span>Tag maintenance</span>
-    </v-card-title>
+    <CardHeading icon="mdi-tag-remove" title="Tag maintenance" />
     <v-card-text>
       <p class="fc-muted text-body-2 mb-4">
         Remove tags with zero image associations and zero series-page
@@ -196,6 +193,7 @@ import { ref } from 'vue'
 
 import { useAdminStore } from '../../stores/admin.js'
 import SampleNameGrid from '../common/SampleNameGrid.vue'
+import CardHeading from '../common/CardHeading.vue'
 
 const store = useAdminStore()
 const preview = ref(null)