refactor(scribe): remove calendar + entity surfaces from web UI (frontend)

Frontend half of the narrowing (milestone #194); matches backend b49efdc.

- delete CalendarView, EventSlideOver, WeatherCard (orphan)
- drop /calendar route + nav link + the g→l keyboard shortcut
- strip the calendar-events API client + event/metadata bits from note
  types and the notes store
- KnowledgeView: remove People/Places/Lists tabs, entity cards, create
  buttons and the upcoming-events widget; keep notes/tasks/plans/processes
  + the overdue-task badge
- NoteEditorView: remove person/place/list forms + list-builder + entity
  metadata; keep note + process editors (type select = Note/Process)
- DashboardView: drop the "Upcoming · 7 days" events rail card
- SettingsView: remove the CalDAV integration card + save/test (its
  endpoints were deleted backend-side)
- prune the now-dead entity/event CSS

RecurrenceEditor + task recurrence rules are kept (task machinery, not
calendar). Verified by a full dangler sweep.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BPtbSzA4JLMAKgFZ8VTg7Q

frontend/src/App.vue

@@ -81,7 +81,6 @@ function onGlobalKeydown(e: KeyboardEvent) {
       case "p": router.push("/projects"); break;
       case "r": router.push("/rules"); break;
       case "g": router.push("/graph"); break;
-      case "l": router.push("/calendar"); break;
       case "x": router.push("/trash"); break;
     }
     return;
@@ -190,12 +189,6 @@ onUnmounted(() => {
                 <kbd class="shortcut-key">p</kbd>
                 <span class="shortcut-desc">Projects</span>
               </div>
-              <div class="shortcut-row">
-                <kbd class="shortcut-key">g</kbd>
-                <span class="shortcut-key-sep">+</span>
-                <kbd class="shortcut-key">l</kbd>
-                <span class="shortcut-desc">Calendar</span>
-              </div>
               <div class="shortcut-row">
                 <kbd class="shortcut-key">g</kbd>
                 <span class="shortcut-key-sep">+</span>