chore(frontend): drop dead settings toggle, types, and store list-surface

Drift-audit Group 7 frontend cleanup (no behavioral change):

- SettingsView: remove the 'auto-consolidate task bodies' toggle and its
  saveAutoConsolidate handler. The auto_consolidate_tasks setting has zero
  backend readers (curator removed in Phase 8); the control did nothing.
- AppSettings type: drop the dead assistant_name / default_model hints (kept
  the open string index signature the store actually uses). Delete the fully
  orphaned types/chat.ts (zero importers).
- notes/tasks Pinia stores: remove the list/filter/sort/pagination surface
  that backed the removed /notes and /tasks list views (verified no consumer
  uses the tasks/notes arrays, refresh, or any filter/sort/pagination method).
  Kept currentNote/currentTask, loading, fetch/create/update/delete, convert,
  patchStatus, startPlanning, backlinks, tags.

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

frontend/src/views/SettingsView.vue

@@ -14,25 +14,10 @@ const toastStore = useToastStore();
 const userTimezone = ref("");
 const savingTimezone = ref(false);
 const timezoneSaved = ref(false);
-const autoConsolidateTasks = ref(true);
-const savingAutoConsolidate = ref(false);
 const trashRetentionDays = ref("90");
 const savingRetention = ref(false);
 const retentionSaved = ref(false);
 
-async function saveAutoConsolidate() {
-  savingAutoConsolidate.value = true;
-  try {
-    await apiPut('/api/settings', {
-      auto_consolidate_tasks: autoConsolidateTasks.value ? "true" : "false",
-    });
-  } catch {
-    toastStore.show('Failed to save setting', 'error');
-  } finally {
-    savingAutoConsolidate.value = false;
-  }
-}
-
 // think_enabled setting removed 2026-05-23. The chat+curator architecture
 // has tools=[] on the chat model; think on a no-tools conversational pass
 // is pure latency cost. See generation_task.py:run_generation comment for
@@ -403,8 +388,6 @@ onMounted(async () => {
   const allSettings = await apiGet<Record<string, string>>("/api/settings");
   userTimezone.value = allSettings.user_timezone ?? "";
   trashRetentionDays.value = allSettings.trash_retention_days ?? "90";
-  // Default true if unset; explicit "false" disables auto-consolidation.
-  autoConsolidateTasks.value = (allSettings.auto_consolidate_tasks ?? "true") !== "false";
   if (allSettings.notify_task_reminders !== undefined) {
     notifyTaskReminders.value = allSettings.notify_task_reminders !== "false";
   }
@@ -992,29 +975,6 @@ function formatUserDate(iso: string): string {
 
     <!-- ── General ── -->
     <div v-show="activeTab === 'general'" class="settings-grid">
-      <!-- Tasks -->
-      <section class="settings-section full-width">
-        <h2>Tasks</h2>
-        <p class="section-desc">
-          Task bodies are auto-summarized from accumulated work logs. The summary runs every few logs, plus on task close.
-        </p>
-        <div class="field">
-          <label class="checkbox-label">
-            <input
-              type="checkbox"
-              v-model="autoConsolidateTasks"
-              :disabled="savingAutoConsolidate"
-              @change="saveAutoConsolidate"
-            />
-            Auto-consolidate task bodies
-          </label>
-          <p class="field-hint">
-            When off, the task body is only refreshed when you click "Re-consolidate"
-            on a task. Existing summaries remain in place.
-          </p>
-        </div>
-      </section>
-
       <!-- Timezone -->
       <section class="settings-section full-width">
         <h2>Timezone</h2>