Phase 19: the copy stops being hardcoded Mandarin

Every `中文 · English` string moves out of ~29 components into
web/src/i18n: one Pack type, a verbatim zh pack, and two ways to read
it — usePack() for components, pack() for the modules that build a line
when something happens rather than when something renders.

Anything with a value in it is a function on the pack rather than a
template at the call site, English pluralisation included: word order
isn't universal, and a pack author has to be able to move the number.
The roster constants (tones, rewrite styles, export formats, companions)
keep only value + emoji, so a label can't drift from its key.

On the server, internal/llm/lang.go replaces "Simplified Chinese" in the
three prompts that actually name her language. pt-PT is spelled
"European Portuguese (pt-PT, never Brazilian Portuguese)" in the prompt
itself, and each Lang carries her word for "why" so the tutor prompt
still recognises the question when she asks it her way.

pair_lang reaches the model through the row-scoped query each handler
already ran — the one that proves she owns the document — rather than a
second lookup that could disagree with it.

Also records Phase 18's deploy: migration 0011 rehearsed against a copy
of the live VPS database, then applied for real.

web/src/components/Companion/useCompanion.ts

@@ -1,16 +1,16 @@
 import { useCallback, useEffect, useRef, useState } from 'react'
 import type { SaveStatus } from '../../hooks/useAutoSave'
 import {
-  BEDTIME,
-  BREAKS,
-  ENCOURAGEMENTS,
-  ERRORS,
-  GREETING,
   MILESTONES,
-  TIPS,
-  WELCOME_BACK,
+  bedtime,
+  breaks,
+  encouragements,
+  errors,
+  greeting,
   milestoneLine,
   pick,
+  tips,
+  welcomeBack,
   type Line,
 } from './tips'
 import { analyzeProse } from './prose'
@@ -60,11 +60,11 @@ const HOVER_GRACE_MS = 3_000 // lingers this long after she stops hovering
 const now = () => Date.now()
 
 // Reading time for a bubble: a base floor by tone, stretched by the combined
-// length of the Mandarin + English lines so denser advice stays up long enough
+// length of the native + English lines so denser advice stays up long enough
 // to actually finish reading.
 function readBubbleMs(b: Bubble): number {
   const base = b.tone === 'cheer' ? CHEER_MS : b.tone === 'bedtime' ? BUBBLE_MS + 4_000 : BUBBLE_MS
-  const chars = b.zh.length + b.en.length
+  const chars = b.native.length + b.en.length
   return Math.min(MAX_BUBBLE_MS, base + chars * READ_MS_PER_CHAR)
 }
 
@@ -138,9 +138,9 @@ export function useCompanion({ wordCount, saveStatus, llmDown, editTick, acceptT
     if (hint) {
       lastRule.current = hint.rule
       recentHints.current = [hint.id, ...recentHints.current].slice(0, 8)
-      return { zh: hint.zh, en: hint.en, tone: 'tip' }
+      return { native: hint.native, en: hint.en, tone: 'tip' }
     }
-    return { ...pick(TIPS), tone: 'tip' }
+    return { ...pick(tips()), tone: 'tip' }
   }, [])
 
   const dismiss = useCallback(() => {
@@ -167,7 +167,7 @@ export function useCompanion({ wordCount, saveStatus, llmDown, editTick, acceptT
 
   // Opening hello (once), after a short beat so it doesn't race the first paint.
   useEffect(() => {
-    const id = setTimeout(() => say({ ...GREETING, tone: 'tip' }), 1200)
+    const id = setTimeout(() => say({ ...greeting(), tone: 'tip' }), 1200)
     return () => clearTimeout(id)
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [])
@@ -183,7 +183,7 @@ export function useCompanion({ wordCount, saveStatus, llmDown, editTick, acceptT
     if (sleeping.current) {
       sleeping.current = false
       sessionStart.current = now() // a fresh stretch starts on return
-      say({ ...WELCOME_BACK, tone: 'cheer' })
+      say({ ...welcomeBack(), tone: 'cheer' })
     } else if (mood === 'sleeping') {
       setMood('idle')
     }
@@ -197,7 +197,7 @@ export function useCompanion({ wordCount, saveStatus, llmDown, editTick, acceptT
       firstAccept.current = false
       return
     }
-    say({ ...pick(ENCOURAGEMENTS), tone: 'cheer' }, { celebrate: true })
+    say({ ...pick(encouragements()), tone: 'cheer' }, { celebrate: true })
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [acceptTick])
 
@@ -229,7 +229,7 @@ export function useCompanion({ wordCount, saveStatus, llmDown, editTick, acceptT
       return
     }
     lastError.current = t
-    say({ ...pick(ERRORS), tone: 'error' }, { sound: 'error' })
+    say({ ...pick(errors()), tone: 'error' }, { sound: 'error' })
   }, [say])
 
   useEffect(() => {
@@ -246,7 +246,7 @@ export function useCompanion({ wordCount, saveStatus, llmDown, editTick, acceptT
   // Occasional gentle cheer on a successful save (kept rare so it isn't noise).
   useEffect(() => {
     if (saveStatus === 'saved' && Math.random() < 0.18) {
-      say({ ...pick(ENCOURAGEMENTS), tone: 'cheer' }, { proactive: true })
+      say({ ...pick(encouragements()), tone: 'cheer' }, { proactive: true })
     }
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [saveStatus])
@@ -267,7 +267,7 @@ export function useCompanion({ wordCount, saveStatus, llmDown, editTick, acceptT
       if (t - sessionStart.current > BREAK_MS && t - lastBreak.current > BREAK_MS) {
         lastBreak.current = t
         sessionStart.current = t
-        say({ ...pick(BREAKS), tone: 'break' }, { proactive: true })
+        say({ ...pick(breaks()), tone: 'break' }, { proactive: true })
         return
       }
 
@@ -276,7 +276,7 @@ export function useCompanion({ wordCount, saveStatus, llmDown, editTick, acceptT
       // returned if she's away/napping).
       if (isBedtime() && t - lastBedtime.current > BEDTIME_GAP) {
         lastBedtime.current = t
-        say({ ...pick(BEDTIME), tone: 'bedtime' }, { proactive: true })
+        say({ ...pick(bedtime()), tone: 'bedtime' }, { proactive: true })
         return
       }