feat(frontend): description field in task editor + Goal block in viewer

Note type gains description and consolidated_at fields. TaskEditorView
adds a Goal textarea above the body editor (wired through dirty/save/
autosave paths). TaskViewerView renders Goal as a subordinate block
above the body, plus a subtle 'Auto-summarized from work logs' banner
when consolidated_at is set.

Also adds a consolidateTask client function for the upcoming
re-consolidate button (Task 11).

frontend/src/api/client.ts

@@ -705,3 +705,14 @@ export interface ProfileObservationEntry {
 
 export const listProfileObservations = () =>
   apiGet<{ observations: ProfileObservationEntry[] }>('/api/profile/observations')
+
+
+// ── Tasks ────────────────────────────────────────────────────────────────────
+
+import type { Note as Task } from '../types/note'
+
+/** Manually trigger a consolidation pass for a task. Returns the freshly-
+ *  updated task with new body + consolidated_at. Bypasses the user's
+ *  auto_consolidate_tasks setting. */
+export const consolidateTask = (id: number) =>
+  apiPost<Task>(`/api/tasks/${id}/consolidate`, {})