Expire trash after 30 days, and make the deadline something you can see

Trash had no end. A note sat in /trash until someone emptied it by hand, and
its attachment BYTES sat on disk the whole time — the pile-up the operator
asked about. Nothing purged; there was no scheduler at all.

Retention is server-owned: `trash_retention_days` (default 30, 0 = keep
forever) in the settings registry, so it lands in admin Settings with no
migration and takes effect without a restart. A background sweep started in
before_serving does the work. Clients learn about a purge the way they learn
about any deletion — as a tombstone on the delta feed.

An auto-purge nobody can see coming is data loss on a timer, so the window is
now visible: /api/config publishes it, notes carry `deleted_at`, Trash leads
with the policy, and each card counts down. The countdown rounds DOWN — saying
"1 day left" for a note with ten minutes on the clock is the one error here
that actually costs someone a note.

Three things this turned up on the way:

- `DELETE /api/notes/<id>` hard-deleted the row, leaving no tombstone at all.
  A permanent delete in the web UI never reached a linked device, which would
  keep its copy forever and push it back on the next edit. It now purges
  through the same path as everything else.
- The purge left `note_revisions` and `note_link_previews` behind. A revision
  holds the full body, so the text of a "permanently deleted" note was still
  sitting in the database.
- `deleted_at` now SURVIVES a purge instead of being cleared. It's still true,
  and it means every query that says "not trashed" excludes tombstones for
  free — without it a content-less row reads as a perfectly normal active note
  and shows up on the board as a blank card.

Desktop keeps its own clock only when there's nobody else to keep one: the
sweep runs at startup on an UNLINKED device and refuses otherwise. A linked
client that expired notes on its own schedule could destroy something the
server was deliberately keeping, then push that delete upstream. Local policy
must never outrank the server's — so it also adopts the server's window for
the countdown rather than showing its offline default.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SreJkbxB4gx8pPsu8QbLPi

frontend/src/components/NoteCard.vue

@@ -14,7 +14,8 @@ import Icon from "./Icon.vue";
 import LinkPreview from "./LinkPreview.vue";
 import MarkdownText from "./MarkdownText.vue";
 import NoteChecklist from "./NoteChecklist.vue";
-import { formatReminder, isOverdue } from "../notes/datetime";
+import { formatReminder, formatTrashCountdown, isOverdue, trashDaysLeft } from "../notes/datetime";
+import { useConfigStore } from "../stores/config";
 
 const props = defineProps<{ note: Note; reorderable?: boolean; active?: boolean }>();
 const emit = defineEmits<{
@@ -24,6 +25,17 @@ const emit = defineEmits<{
   (e: "drop", note: Note): void;
 }>();
 const notes = useNotesStore();
+const config = useConfigStore();
+
+// --- Retention countdown. A note in Trash is on a clock, and the card is the only
+// place someone browsing Trash would ever find that out in time to restore it.
+// Null whenever nothing is going to happen: not trashed, or retention turned off. ---
+const trashDays = computed(() =>
+  props.note.trashed ? trashDaysLeft(props.note.deleted_at, config.trashRetentionDays) : null,
+);
+const trashCountdown = computed(() => formatTrashCountdown(trashDays.value));
+// Same red the overdue reminder uses — the last few days are worth noticing.
+const trashUrgent = computed(() => trashDays.value !== null && trashDays.value <= 3);
 
 // The card previews the first image inline; non-image files show as compact chips.
 const firstImage = computed(() => props.note.attachments.find((a) => a.mime.startsWith("image/")));
@@ -236,6 +248,32 @@ onBeforeUnmount(() => document.removeEventListener("mousedown", onDocMousedown))
       </span>
     </div>
 
+    <div v-if="trashCountdown" class="mt-2">
+      <span
+        class="inline-flex items-center gap-1 rounded-full px-2 py-0.5 text-xs"
+        :class="
+          trashUrgent
+            ? 'bg-red-100 text-red-700 dark:bg-red-950/50 dark:text-red-300'
+            : 'bg-black/5 text-neutral-600 dark:bg-white/10 dark:text-neutral-300'
+        "
+        :title="`Permanently deleted ${config.trashRetentionDays} days after it was trashed`"
+      >
+        <svg
+          class="h-3 w-3"
+          viewBox="0 0 24 24"
+          fill="none"
+          stroke="currentColor"
+          stroke-width="2"
+          stroke-linecap="round"
+          stroke-linejoin="round"
+        >
+          <circle cx="12" cy="12" r="10" />
+          <polyline points="12 6 12 12 16 14" />
+        </svg>
+        {{ trashCountdown }}
+      </span>
+    </div>
+
     <!-- Toolbar overlays the card's top-right on hover/focus as a floating pill
          (window-control style) instead of reserving a permanent row — so at rest
          the card is content-sized with even padding, not text pinned to the top

frontend/src/components/NoteEditor.vue

@@ -65,6 +65,7 @@ const draftNote = computed<Note>(() => ({
   pinned: false,
   archived: false,
   trashed: false,
+  deleted_at: null,
   remind_at: null,
   recurrence: null,
   labels: labelList.value,