feat(settings): surface the near-duplicate (pHash) control + reorder import tab

The phash_threshold knob (controls whether edits/variants of an image are
dropped as near-duplicates on import) was buried at the bottom of the import
filters form and labelled opaquely, so it read as 'missing'. Hoist it to the
TOP of the form as a 'Near-duplicate sensitivity' section: a labelled slider
(Exact / Strict / Default / Loose stops, 0-16) for the gist + the precise
number field, both bound to phash_threshold, with copy that says plainly to
lower it if variants are being dropped.

Also swap the import-tab order to filters → trigger → recent-tasks (filters on
top per operator); the task list stays directly under the trigger for hit/miss
feedback adjacency.

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

frontend/src/components/settings/ImportFiltersForm.vue

@@ -2,6 +2,42 @@
   <v-card>
     <v-card-title>Import filters</v-card-title>
     <v-card-text v-if="store.settings">
+      <!-- Near-duplicate dedup sensitivity, hoisted to the top: it's the
+           most-asked knob — too loose and edits/variants of the same image
+           get dropped as duplicates on import. Slider with sane labelled
+           stops for the gist + a number field for precision; both bind the
+           same phash_threshold. -->
+      <div class="fc-phash">
+        <div class="fc-phash__title">Near-duplicate sensitivity</div>
+        <div class="fc-help mb-1">
+          How aggressively imports merge look-alike images (perceptual-hash
+          distance). <strong>Lower it if edits/variants of the same image are
+          being dropped as duplicates;</strong> raise it to collapse more
+          look-alikes. Applies to new imports.
+        </div>
+        <v-row align="center" no-gutters>
+          <v-col cols="12" sm="9">
+            <v-slider
+              v-model="local.phash_threshold"
+              :min="0" :max="16" :step="1"
+              :ticks="PHASH_TICKS" show-ticks="always" tick-size="4"
+              thumb-label color="accent" hide-details
+              class="fc-phash__slider"
+              @end="save"
+            />
+          </v-col>
+          <v-col cols="8" sm="3" class="ps-sm-4 mt-2 mt-sm-0">
+            <v-text-field
+              v-model.number="local.phash_threshold"
+              label="Distance" type="number" min="0"
+              density="compact" hide-details @blur="save"
+            />
+          </v-col>
+        </v-row>
+      </div>
+
+      <v-divider class="my-5" />
+
       <v-row>
         <v-col cols="12" sm="6">
           <v-text-field
@@ -41,14 +77,6 @@
             :disabled="!local.skip_single_color" @end="save"
           />
         </v-col>
-        <v-col cols="12" sm="6">
-          <v-text-field
-            v-model.number="local.phash_threshold"
-            label="Perceptual-hash threshold" type="number" min="0"
-            density="compact" hide-details @blur="save"
-          />
-          <div class="fc-help">Higher = looser near-duplicate matching.</div>
-        </v-col>
       </v-row>
 
       <v-alert v-if="store.settingsError" type="error" variant="tonal" class="mt-2" closable>
@@ -66,6 +94,9 @@ import { reactive, watch } from 'vue'
 import { useImportStore } from '../../stores/import.js'
 
 const store = useImportStore()
+// Labelled stops so the less-initiated get the gist without knowing what a
+// Hamming distance is. 0 = byte-for-byte only; 10 = the shipped default.
+const PHASH_TICKS = { 0: 'Exact', 4: 'Strict', 10: 'Default', 16: 'Loose' }
 // Downloader + schedule-defaults fields moved to
 // /subscriptions?tab=settings (operator decision 2026-05-27). This form
 // now only owns image-import filters.
@@ -89,4 +120,11 @@ async function save() {
   color: rgb(var(--v-theme-on-surface-variant));
   margin-top: 2px;
 }
+.fc-phash__title {
+  font-size: 0.95rem;
+  font-weight: 600;
+  color: rgb(var(--v-theme-on-surface));
+}
+/* Headroom so the tick labels (Exact/Strict/Default/Loose) aren't clipped. */
+.fc-phash__slider { margin-bottom: 18px; }
 </style>

frontend/src/views/SettingsView.vue

@@ -44,14 +44,15 @@
       </v-window-item>
 
       <v-window-item value="import">
-        <!-- Order: trigger → recent tasks → filters. Tasks sit directly
-             below the trigger so operator sees hit/miss feedback without
-             scrolling past the filter card (operator-flagged 2026-05-25). -->
+        <!-- Order: filters → trigger → recent tasks. Filters hoisted above the
+             trigger (operator-flagged 2026-06-04); the task list stays
+             directly below the trigger so hit/miss feedback is adjacent to the
+             button that produced it (operator-flagged 2026-05-25). -->
+        <ImportFiltersForm />
+        <v-divider class="my-6" />
         <ImportTriggerPanel />
         <v-divider class="my-6" />
         <ImportTaskList />
-        <v-divider class="my-6" />
-        <ImportFiltersForm />
       </v-window-item>
 
       <v-window-item value="cleanup">