feat: companion 核心的人設注入、語氣、心情標記與互動記憶

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

plugins/cockpit/companion/affinity.ts

@@ -0,0 +1,60 @@
+import { clamp } from './types.ts'
+
+export const GAIN = 0.01
+export const DAILY_CAP = 0.05
+export const LOSS = 0.03
+export const IDLE_DAYS = 7
+export const HALF_LIFE_DAYS = 30
+const DAY = 86_400_000
+
+export type Stage = 0 | 1 | 2 | 3
+export const STAGE_NAMES = ['陌生', '熟悉', '親近', '特別'] as const
+
+// 升階門檻；降階門檻 = 升階 − 0.05（遲滯）
+const UP = [0.1, 0.3, 0.6]
+const HYST = 0.05
+
+export type Affinity = {
+  value: number
+  stage: Stage
+  /** 今日已增加量與其日期 */
+  gainDay: string
+  gainToday: number
+  lastSeen: number
+}
+
+export const initialAffinity = (now: number): Affinity => ({ value: 0, stage: 0, gainDay: dayKey(now), gainToday: 0, lastSeen: now })
+
+export const dayKey = (t: number) => new Date(t).toISOString().slice(0, 10)
+
+export function stageFor(value: number, prev: Stage): Stage {
+  let s = prev
+  while (s < 3 && value >= UP[s]!) s++
+  while (s > 0 && value < UP[s - 1]! - HYST) s--
+  return s as Stage
+}
+
+/** 讀取時計算：離開超過 7 天後以 30 天半衰期回到 0 */
+export function settle(a: Affinity, now: number): Affinity {
+  const idleDays = (now - a.lastSeen) / DAY
+  if (idleDays <= IDLE_DAYS) return a
+  const f = Math.pow(0.5, (idleDays - IDLE_DAYS) / HALF_LIFE_DAYS)
+  const value = a.value * f
+  return { ...a, value, stage: stageFor(value, a.stage), lastSeen: now }
+}
+
+export function meaningful(a: Affinity, now: number): Affinity {
+  const s = settle(a, now)
+  const today = dayKey(now)
+  const gainToday = s.gainDay === today ? s.gainToday : 0
+  const gain = clamp(Math.min(GAIN, DAILY_CAP - gainToday), 0, GAIN)
+  const value = clamp(s.value + gain, -1, 1)
+  return { value, stage: stageFor(value, s.stage), gainDay: today, gainToday: gainToday + gain, lastSeen: now }
+}
+
+export function negative(a: Affinity, now: number): Affinity {
+  const s = settle(a, now)
+  const value = clamp(s.value - LOSS, -1, 1)
+  const today = dayKey(now)
+  return { ...s, value, stage: stageFor(value, s.stage), gainDay: today, gainToday: s.gainDay === today ? s.gainToday : 0, lastSeen: now }
+}