refactor(ui): consolidate 7 hand-rolled kebabs into one KebabMenu (DRY pattern sweep)

First pattern-consistency DRY pass (process #594). The overflow kebab was
hand-rolled 7 ways in two divergent activator strategies — Pattern A
(#activator + v-bind) which silently breaks inside the teleported image modal
(#711), and Pattern B (manual v-model + activator=parent + open-on-click=false +
z-index 2400) the modal kebabs needed as a workaround.

New <KebabMenu> (components/common) bakes in the modal-safe strategy
UNIVERSALLY, so every kebab works in modal and non-modal contexts — folding the
latent #711-class bug fix into all five Pattern-A sites. Menu items go in the
default slot; variations (size/variant/location/label/min-width) are props.

Adopted across all 7: TagChip, SuggestionItem, TagCard, SeriesView card,
SeriesManageView, BackupRunsTable, SourceActions. Exhaustiveness (§8b):
mdi-dots-vertical now lives only in KebabMenu. Labeled dropdowns / nav menus /
filter popovers are a different concept and left alone. Seeded the pattern
catalog so new code reuses the primitive. Test: KebabMenu renders slot items +
trigger label/glyph + presentational props.

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

frontend/src/views/SeriesView.vue

@@ -60,27 +60,20 @@
               <span v-if="s.has_gap" class="fc-sbcard__gap" title="Has a missing-page gap">
                 <v-icon size="x-small">mdi-alert-outline</v-icon> gap
               </span>
-              <v-menu>
-                <template #activator="{ props: menuProps }">
-                  <v-btn
-                    v-bind="menuProps"
-                    icon="mdi-dots-vertical" size="x-small" variant="flat"
-                    class="fc-sbcard__kebab" :aria-label="`Actions for ${s.name}`"
-                    @click.stop
-                  />
-                </template>
-                <v-list density="compact">
-                  <v-list-item prepend-icon="mdi-pencil" @click.stop="openRename(s)">
-                    <v-list-item-title>Rename</v-list-item-title>
-                  </v-list-item>
-                  <v-list-item
-                    prepend-icon="mdi-delete" base-color="error"
-                    @click.stop="openDelete(s)"
-                  >
-                    <v-list-item-title>Delete</v-list-item-title>
-                  </v-list-item>
-                </v-list>
-              </v-menu>
+              <KebabMenu
+                class="fc-sbcard__kebab" variant="flat"
+                :label="`Actions for ${s.name}`"
+              >
+                <v-list-item prepend-icon="mdi-pencil" @click.stop="openRename(s)">
+                  <v-list-item-title>Rename</v-list-item-title>
+                </v-list-item>
+                <v-list-item
+                  prepend-icon="mdi-delete" base-color="error"
+                  @click.stop="openDelete(s)"
+                >
+                  <v-list-item-title>Delete</v-list-item-title>
+                </v-list-item>
+              </KebabMenu>
             </div>
             <div class="fc-sbcard__body">
               <h3 class="fc-sbcard__name">{{ s.name }}</h3>
@@ -210,6 +203,7 @@ import { useRouter } from 'vue-router'
 import { useSeriesBrowseStore } from '../stores/seriesBrowse.js'
 import { useSeriesSuggestionsStore } from '../stores/seriesSuggestions.js'
 import TagRenameDialog from '../components/modal/TagRenameDialog.vue'
+import KebabMenu from '../components/common/KebabMenu.vue'
 
 const router = useRouter()
 const store = useSeriesBrowseStore()