feat: brainstorm sessions, PDF document Q&A, embedding fixes, and UI improvements

- Add brainstorm feature with collaborative canvas, AI idea generation, live cursors, playback, and export
- Add PDF upload/extraction/ingestion pipeline with pgvector document search (RAG)
- Add document Q&A overlay with streaming chat and PDF preview
- Add note attachments UI with status polling, grid layout, and auto-scroll
- Add task extraction AI tool and agent executor improvements
- Fix NoteEmbedding missing updatedAt column, re-index 66 notes with 1536-dim embeddings
- Fix brainstorm 'Create Note' button: add success toast and redirect to created note
- Fix memory echo notification infinite polling
- Fix chat route to always include document_search tool
- Add brainstorm i18n keys across all 14 locales
- Add socket server for real-time brainstorm collaboration
- Add hierarchical notebook selector and organize notebook dialog improvements
- Add sidebar brainstorm section with session management
- Update prisma schema with brainstorm tables, attachments, and document chunks

memento-note/lib/utils/format-localized-date.ts

@@ -0,0 +1,74 @@
+import { format, type Locale } from 'date-fns'
+import { toJalaali } from 'jalaali-js'
+
+const JALALI_MONTHS_FA = [
+  'فروردین',
+  'اردیبهشت',
+  'خرداد',
+  'تیر',
+  'مرداد',
+  'شهریور',
+  'مهر',
+  'آبان',
+  'آذر',
+  'دی',
+  'بهمن',
+  'اسفند',
+] as const
+
+const PERSIAN_DIGITS = ['۰', '۱', '۲', '۳', '۴', '۵', '۶', '۷', '۸', '۹'] as const
+
+/** Western digits → Persian (Extended Arabic-Indic) numerals, e.g. 1405 → ۱۴۰۵ */
+export function toPersianDigits(input: string): string {
+  return input.replace(/\d/g, (ch) => PERSIAN_DIGITS[Number(ch)] ?? ch)
+}
+
+function pad2(n: number): string {
+  return n < 10 ? `0${n}` : `${n}`
+}
+
+function formatJalaliAbsolute(date: Date, pattern: string): string {
+  const { jy, jm, jd } = toJalaali(date)
+  const monthName = JALALI_MONTHS_FA[jm - 1]
+  const h = pad2(date.getHours())
+  const min = pad2(date.getMinutes())
+
+  let s: string
+  switch (pattern) {
+    case 'd MMM yyyy':
+      s = `${jd} ${monthName} ${jy}`
+      break
+    case 'd MMM yyyy · HH:mm':
+      s = `${jd} ${monthName} ${jy} · ${h}:${min}`
+      break
+    case 'd MMM yyyy HH:mm':
+      s = `${jd} ${monthName} ${jy} ${h}:${min}`
+      break
+    case 'd MMM · HH:mm':
+      s = `${jd} ${monthName} · ${h}:${min}`
+      break
+    case 'MMM d, yyyy':
+      s = `${monthName} ${jd}، ${jy}`
+      break
+    default:
+      s = `${jd} ${monthName} ${jy}`
+  }
+  return toPersianDigits(s)
+}
+
+/**
+ * Absolute calendar dates for Persian (`fa`) use the Solar Hijri (Jalali / هجری شمسی) calendar.
+ * Times remain in the user's local timezone. For relative phrases, keep using `formatDistanceToNow` with `faIR`.
+ */
+export function formatAbsoluteDateLocalized(
+  date: Date | string,
+  language: string,
+  pattern: string,
+  locale: Locale
+): string {
+  const d = typeof date === 'string' ? new Date(date) : date
+  if (language === 'fa') {
+    return formatJalaliAbsolute(d, pattern)
+  }
+  return format(d, pattern, { locale })
+}