Finish Phase 22: the half of Petal that works with the tunnel down

Grammar lite, the false-friend list, the daily invitation and the offline
miscollocations — the four remaining §5–§6 items, all client-side and all
alive on a box that cannot reach the model.

The offline collocations forced a schema change. `type` had been doubling
as the answer to "which engine found this" — `mechanics` meant offline —
and that stops being true the moment an offline rule proposes a
collocation. Migration 0013 adds `source` (llm | local) and every pass now
scopes its DELETE by engine; without it the coach silently wiped every
offline chunk on the page. Existing rows backfill by type, so a pre-0013
collocation row is claimed as the coach's, which it was: the offline list
did not exist yet.

The rule pack is hand-curated rather than mined, and the entries left out
are the point — `married with` is wrong until "married with children",
`arrive to` wants at or in depending on the noun. A pack running on every
keystroke must not correct correct writing.

Claude-Session: https://claude.ai/code/session_016y6gyuHkQXPiEuW8RGQyua

web/src/i18n/packs/zh.ts

@@ -99,6 +99,25 @@ export const zh: Pack = {
       en: `Wow — ${words} words already! Amazing. 🎉`,
     }),
 
+    // A small thing to write about, offered once a day to an empty page. Each
+    // one is a memory or an opinion rather than an exercise — nothing here can
+    // be got wrong, which is the point. Fifty words is a deliberately small ask.
+    invitations: [
+      { native: '写 50 个字：今天让你微笑的一件小事 🌸', en: 'Write 50 words: one small thing that made you smile today.' },
+      { native: '写 50 个字：今天吃到最好吃的东西', en: 'Write 50 words: the best thing you ate today.' },
+      { native: '写 50 个字：你现在窗外看到了什么？', en: "Write 50 words: what you can see out of your window right now." },
+      { native: '写 50 个字：一个你很想再去一次的地方', en: 'Write 50 words: somewhere you would happily go back to.' },
+      { native: '写 50 个字：这个星期学到的一件事', en: 'Write 50 words: one thing you learned this week.' },
+      { native: '写 50 个字：给一年后的自己说句话', en: 'Write 50 words: something to tell yourself a year from now.' },
+      { native: '写 50 个字：最近听到的一首歌', en: 'Write 50 words: a song you have had on lately.' },
+      { native: '写 50 个字：今天想谢谢谁？', en: 'Write 50 words: someone you would like to thank today.' },
+    ],
+    inviteAccept: '好，来写 · Let’s write',
+    inviteDecline: '今天不了 · Not today',
+    // The entire consequence of saying no. No streak was broken, because there
+    // is no streak.
+    declined: { native: '好吧，我继续睡 😴', en: 'Fair enough — back to my nap. 😴' },
+
     // Keyed by the companion ids in Companion/companions.ts.
     names: {
       cat: '瞌睡猫',
@@ -131,8 +150,23 @@ export const zh: Pack = {
     itsOwn: '“it’s” = “it is”；表示“它的”要用 “its”，所以是 “its own”。',
     itsIs: (rest) => `这里应该是 “it’s ${rest}”（it is），“its” 是“它的”。`,
     thanNotThen: (word) => `比较的时候用 “than”，不是 “then”：“${word} than”。`,
+    preposition: (wrong, right) => `英文习惯说 “${right}”，不是 “${wrong}”，这个介词是固定搭配。`,
+    collocation: (wrong, right) => `英文里这两个词一般这样搭：“${right}”，而不是 “${wrong}”。`,
+    doubleComparative: (lead, word) => `“${word}” 本身已经是比较级了，前面不用再加 “${lead}”：写 “${word}” 就好。`,
+    peopleArePlural: (verb) => `“people” 在英文里是复数，要用 “people ${verb}”。`,
+    ageIsNotHave: (years) => `英文说年龄用 be 动词，不是 have：“I am ${years} years old”。`,
+    agreeIsAVerb: '“agree” 本身就是动词，前面不用加 be：说 “I agree” 就好。',
+    forNotSince: (duration) => `表示持续了多久用 “for”：“for ${duration}”；“since” 后面接的是起点（since 2020）。`,
+    veryBeforeVerb: (verb) => `“very” 只能修饰形容词，不能直接放在动词前面：可以说 “really ${verb}”，或者 “${verb} … very much”。`,
+    turnOnNotOpen: (thing, on) => `英文里电器是 turn ${on ? 'on' : 'off'}，不用 open/close：“turn ${on ? 'on' : 'off'} the ${thing}”。`,
+    althoughOrBut: (word) => `英文里 “${word}” 和 “but” 只用一个就够了，不像中文的“虽然…但是…”。`,
   },
 
+  // The zh pair has no false friends: the trap needs a shared script, and 汉字
+  // and the Latin alphabet never look alike. An empty list here is the honest
+  // answer, not an unwritten one.
+  falseFriends: {},
+
   docs: {
     sortRecent: '最近 · Recent',
     sortTitle: '标题 · Title',