feat(app): initial i18n stubbing

packages/app/src/context/language.tsx

@@ -0,0 +1,77 @@
+import * as i18n from "@solid-primitives/i18n"
+import { createEffect, createMemo } from "solid-js"
+import { createStore } from "solid-js/store"
+import { createSimpleContext } from "@opencode-ai/ui/context"
+import { Persist, persisted } from "@/utils/persist"
+import { dict as en } from "@/i18n/en"
+import { dict as zh } from "@/i18n/zh"
+
+export type Locale = "en" | "zh"
+
+type RawDictionary = typeof en
+type Dictionary = i18n.Flatten<RawDictionary>
+
+const LOCALES: readonly Locale[] = ["en", "zh"]
+
+function detectLocale(): Locale {
+  if (typeof navigator !== "object") return "en"
+
+  const languages = navigator.languages?.length ? navigator.languages : [navigator.language]
+  for (const language of languages) {
+    if (!language) continue
+    if (language.toLowerCase().startsWith("zh")) return "zh"
+  }
+
+  return "en"
+}
+
+export const { use: useLanguage, provider: LanguageProvider } = createSimpleContext({
+  name: "Language",
+  init: () => {
+    const [store, setStore, _, ready] = persisted(
+      Persist.global("language", ["language.v1"]),
+      createStore({
+        locale: detectLocale() as Locale,
+      }),
+    )
+
+    const locale = createMemo<Locale>(() => (store.locale === "zh" ? "zh" : "en"))
+
+    createEffect(() => {
+      const current = locale()
+      if (store.locale === current) return
+      setStore("locale", current)
+    })
+
+    const base = i18n.flatten(en)
+    const dict = createMemo<Dictionary>(() => {
+      if (locale() === "en") return base
+      return { ...base, ...i18n.flatten(zh) }
+    })
+
+    const t = i18n.translator(dict, i18n.resolveTemplate)
+
+    const labelKey: Record<Locale, keyof Dictionary> = {
+      en: "language.en",
+      zh: "language.zh",
+    }
+
+    const label = (value: Locale) => t(labelKey[value])
+
+    createEffect(() => {
+      if (typeof document !== "object") return
+      document.documentElement.lang = locale()
+    })
+
+    return {
+      ready,
+      locale,
+      locales: LOCALES,
+      label,
+      t,
+      setLocale(next: Locale) {
+        setStore("locale", next)
+      },
+    }
+  },
+})