feat(bot): add topic history-aware assistant replies

apps/bot/src/topic-history.ts

@@ -0,0 +1,66 @@
+import { nowInstant, Temporal, type Instant } from '@household/domain'
+import type { TopicMessageHistoryRecord } from '@household/ports'
+
+export interface TopicHistoryTurn {
+  role: 'user' | 'assistant'
+  speaker: string
+  text: string
+  threadId: string | null
+}
+
+const MEMORY_LOOKUP_PATTERN =
+  /\b(?:do you remember|remember|what were we talking about|what did we say today)\b|(?:^|[^\p{L}])(?:помнишь|ты\s+помнишь|что\s+мы\s+сегодня\s+обсуждали|о\s+чем\s+мы\s+говорили)(?=$|[^\p{L}])/iu
+
+export function shouldLoadExpandedChatHistory(text: string): boolean {
+  return MEMORY_LOOKUP_PATTERN.test(text.trim())
+}
+
+export function startOfCurrentDayInTimezone(
+  timezone: string,
+  referenceInstant = nowInstant()
+): Instant {
+  const zoned = referenceInstant.toZonedDateTimeISO(timezone)
+  const startOfDay = Temporal.ZonedDateTime.from({
+    timeZone: timezone,
+    year: zoned.year,
+    month: zoned.month,
+    day: zoned.day,
+    hour: 0,
+    minute: 0,
+    second: 0,
+    millisecond: 0,
+    microsecond: 0,
+    nanosecond: 0
+  })
+
+  return startOfDay.toInstant()
+}
+
+export function historyRecordToTurn(record: TopicMessageHistoryRecord): TopicHistoryTurn {
+  return {
+    role: record.isBot ? 'assistant' : 'user',
+    speaker: record.senderDisplayName ?? (record.isBot ? 'Kojori Bot' : 'Unknown'),
+    text: record.rawText.trim(),
+    threadId: record.telegramThreadId
+  }
+}
+
+export function formatThreadHistory(turns: readonly TopicHistoryTurn[]): string | null {
+  const lines = turns
+    .map((turn) => `${turn.speaker} (${turn.role}): ${turn.text}`)
+    .filter((line) => line.trim().length > 0)
+
+  return lines.length > 0 ? lines.join('\n') : null
+}
+
+export function formatSameDayChatHistory(turns: readonly TopicHistoryTurn[]): string | null {
+  const lines = turns
+    .map((turn) =>
+      turn.threadId
+        ? `[thread ${turn.threadId}] ${turn.speaker} (${turn.role}): ${turn.text}`
+        : `${turn.speaker} (${turn.role}): ${turn.text}`
+    )
+    .filter((line) => line.trim().length > 0)
+
+  return lines.length > 0 ? lines.join('\n') : null
+}