feat(system-tags): process auto-tag settings UI + mode-aware review strip (#1464)

Frontend for the system-tag refactor (milestone #157 step 6).

- HeadsCard: new 'Auto-tag work-in-progress' section (enable + tag-confidence +
  conflict knobs) for wip/editor process auto-apply, mirroring the chrome card;
  copy notes they stay VISIBLE and the head only learns from titles/manual (no
  runaway). Presentation copy narrowed to banner-only.
- HiddenReviewStrip: mode-aware — chrome flags read 'hidden as X / Keep hidden /
  Un-hide'; process flags read 'auto-tagged X / Keep tag / Remove tag'. Same
  endpoints (the backend returns mode), different words.

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

frontend/src/components/settings/HeadsCard.vue

@@ -171,13 +171,13 @@
         />
       </div>
       <p class="fc-muted text-body-2 mb-3">
-        Auto-hide banners and editor screenshots from the gallery once a head has
-        learned them (≥ {{ minPositives }} examples) and clears
+        Auto-hide <code>banner</code> chrome from the gallery once a head has
+        learned it (≥ {{ minPositives }} examples) and clears
         {{ Math.round((presentationThresholdInput || 0) * 100) }}% confidence.
-        <code>wip</code> is never auto-hidden. If a hidden image also looks like
-        real content (≥ {{ Math.round((presentationConflictInput || 0) * 100) }}%
-        on a content tag), it's flagged in the Hidden view instead of buried.
-        Every auto-hide is reversible.
+        (<code>wip</code> and <code>editor screenshot</code> are handled by the
+        process auto-tagger below.) If a hidden image also looks like real content
+        (≥ {{ Math.round((presentationConflictInput || 0) * 100) }}% on a content
+        tag), it's flagged for review instead of buried. Every auto-hide is reversible.
       </p>
       <div class="d-flex mb-3" style="gap: 12px;">
         <v-text-field
@@ -195,6 +195,43 @@
       </div>
     </div>
 
+    <!-- Process auto-tagging (#1464): wip / editor screenshot -->
+    <div class="fc-auto mt-6">
+      <div class="d-flex align-center mb-1" style="gap: 10px;">
+        <v-icon size="18" color="accent">mdi-progress-wrench</v-icon>
+        <span class="fc-section-h">Auto-tag work-in-progress</span>
+        <v-switch
+          v-model="processEnabled" :loading="settingBusy" hide-details
+          density="compact" color="success" class="ml-auto"
+          @update:model-value="onToggleProcess"
+        />
+      </div>
+      <p class="fc-muted text-body-2 mb-3">
+        Auto-tag <code>wip</code> and <code>editor screenshot</code> process art
+        once a head has learned them (≥ {{ minPositives }} examples) and clears
+        {{ Math.round((processThresholdInput || 0) * 100) }}% confidence. These stay
+        <strong>visible</strong> in the gallery — the tag just keeps them out of
+        training and the Explore rabbit-hole. Off by default. If a tagged image also
+        looks like real content (≥ {{ Math.round((processConflictInput || 0) * 100) }}%
+        on a content tag), it's flagged for review. Learns only from your titles +
+        manual tags, never its own guesses — so it can't run away. Every tag reversible.
+      </p>
+      <div class="d-flex mb-3" style="gap: 12px;">
+        <v-text-field
+          v-model.number="processThresholdInput" label="Tag confidence"
+          type="number" min="0.5" max="0.999" step="0.01" density="compact"
+          hide-details style="max-width: 200px;" :disabled="settingBusy"
+          @change="onSaveProcess"
+        />
+        <v-text-field
+          v-model.number="processConflictInput" label="Flag if content ≥"
+          type="number" min="0" max="1" step="0.05" density="compact"
+          hide-details style="max-width: 200px;" :disabled="settingBusy"
+          @change="onSaveProcess"
+        />
+      </div>
+    </div>
+
     <!-- Performance / tuning -->
     <div v-if="metricsConcepts.length" class="mt-5">
       <div class="fc-section-h mb-1">How auto-apply is landing</div>
@@ -258,6 +295,9 @@ let autoTimer = null
 const presentationEnabled = ref(true)
 const presentationThresholdInput = ref(0.90)
 const presentationConflictInput = ref(0.50)
+const processEnabled = ref(false)
+const processThresholdInput = ref(0.90)
+const processConflictInput = ref(0.50)
 
 const autoRunning = computed(() => autoStatus.value?.running_id != null)
 const lastSweep = computed(() =>
@@ -292,6 +332,9 @@ onMounted(async () => {
     presentationEnabled.value = s.presentation_auto_apply_enabled ?? true
     presentationThresholdInput.value = s.presentation_auto_apply_threshold ?? 0.90
     presentationConflictInput.value = s.presentation_conflict_threshold ?? 0.50
+    processEnabled.value = s.process_auto_apply_enabled ?? false
+    processThresholdInput.value = s.process_auto_apply_threshold ?? 0.90
+    processConflictInput.value = s.process_conflict_threshold ?? 0.50
   } catch { /* non-fatal */ }
   await refresh()
   if (running.value) startPoll()
@@ -402,6 +445,32 @@ async function onSavePresentation() {
     settingBusy.value = false
   }
 }
+
+async function onToggleProcess(val) {
+  settingBusy.value = true
+  try {
+    await mlSettings.patchSettings({ process_auto_apply_enabled: !!val })
+    toast({ text: val ? 'WIP auto-tag on' : 'WIP auto-tag off', type: 'success' })
+  } catch (e) {
+    processEnabled.value = !val   // revert the switch
+    toast({ text: `Could not update: ${e.message}`, type: 'error' })
+  } finally {
+    settingBusy.value = false
+  }
+}
+async function onSaveProcess() {
+  settingBusy.value = true
+  try {
+    await mlSettings.patchSettings({
+      process_auto_apply_threshold: Number(processThresholdInput.value),
+      process_conflict_threshold: Number(processConflictInput.value),
+    })
+  } catch (e) {
+    toast({ text: `Could not save: ${e.message}`, type: 'error' })
+  } finally {
+    settingBusy.value = false
+  }
+}
 function onPreview() { startSweep(true) }
 function onApplyNow() { startSweep(false) }
 async function startSweep(dryRun) {