fix(dev): Linux tauri:dev fails to start (Initialization Failed + i18n store-undefined crash)

[Raymond8196]

Description

On Linux, pnpm tauri:dev fails to reach the main UI. Two related but
distinct startup failures block the app:

1. "Initialization Failed" — WebKitGTK cannot load the App module chunk.
2. i18n crash requiring reload — even when the chunk loads, a slow cold
   start lets React mount before i18n.init() completes, crashing with
   undefined is not an object (evaluating 'this.store.hasLanguageSomeTranslations').

Both are dev-only regressions that do not affect production builds.

Steps to Reproduce

Run on Linux (WebKitGTK-based WebView):

pnpm install
pnpm tauri:dev

Symptom 1 (Initialization Failed): The window shows the emergency
"Initialization Failed" screen instead of the main UI.

Symptom 2 (i18n crash): On a cold first launch the app throws
undefined is not an object (evaluating 'this.store.hasLanguageSomeTranslations')
and the user is forced to reload; after reload it works (cache is warm,
init finishes within the timeout).

Expected Behavior

pnpm tauri:dev should reach the main UI directly on the first launch,
without the emergency screen and without needing a manual reload.

Actual Behavior

Root cause 1 — App chunk un-loadable by WebKitGTK

Since e06f4b471 ("isolate dual-instance cloud collaboration"), App is
loaded via a runtime dynamic import("@src/App"), which webpack emits as
a separate chunk. Under eval-cheap-module-source-map that chunk inlines
every module's source and balloons to ~77MB; WebKitGTK fails the runtime
dynamic import → "Initialization Failed". Even after moving the source
map out of the chunk, WebKitGTK still fails the runtime dynamic import
— the trigger is the loading mechanism, not only the size.

Root cause 2 — i18n loses the init race

src/index.tsx wraps the parallel init in a 10s Promise.race:

const initPromise = Promise.all([
  i18nReady,          // async: loads locale JSON → i18n.init()
  initTheme(),
  initializeTauriAPIs(),
  initBackgroundImage(),
  appModulePromise,
]);
await Promise.race([initPromise, timeoutPromise]);  // 10s
// rejection swallowed → React mounts

On a slow cold start the race is lost; the rejection is swallowed and
React mounts before i18n.init() completes. The first useTranslation()
call then hits i18next's not-yet-initialized this.store → crash.
i18n is not degradable (App calls useTranslation() unconditionally
at render), so it must be ready before mount.

Environment

• OS: Ubuntu 22.04 (WebKitGTK)
• App version / commit: current develop (verified affected up to 20cbbd888)
• Runtime: dev (pnpm tauri:dev); production builds are unaffected

Additional Context

Fix is on branch fix/dev-init-webkit-chunk (two commits):

• 2e38474e4 — dev-only: bundle App into main.js via
  webpackMode: "eager"; switch dev devtool from
  eval-cheap-module-source-map to cheap-source-map (separate .map
  file) so the executable bundle stays ~41MB. Production is untouched
  (prod keeps the normal dynamic import and devtool: false).
• 1aa39a30a — pull i18nReady out of the bounded Promise.race and
  await it unconditionally after the degradable ops settle; on rejection
  surface the emergency error UI instead of mounting a guaranteed-to-crash
  React tree.