refactor(web-panel): update architecture + cheat i18n

Reorganize the panel around product capabilities and integrate the
remote i18n feature from origin/master into the new structure.

- Restructure src into capability features (app, trainer, library,
  remote-session, appearance, shared); move the bridge to bridge/src.
- Add lingui-based UI localization and wrap remaining user-facing
  strings (Trans / msg macros); fix the 'END В·' mojibake.
- Port WeMod cheat-metadata i18n: capture the access token from the
  snapshot's renderer in the bridge and fetch localized trainer_meta
  in remote-session.i18n; guarantee snapshot sync on token failure.
- Wire vitest to the app's lingui/preact pipeline (mergeConfig).

web-panel/src/shared/storage.ts

@@ -0,0 +1,78 @@
+import type { TrainerSummary } from '../../protocol/messages';
+
+type Reviver<T> = (raw: unknown) => T | null;
+
+function getStore(): Storage | null {
+  return typeof window === 'undefined' ? null : window.localStorage;
+}
+
+export function getTrainerStorageId(trainer: TrainerSummary | null | undefined): string | null {
+  if (!trainer) {
+    return null;
+  }
+
+  const id = trainer.gameId?.trim() || trainer.titleId?.trim() || trainer.trainerId?.trim();
+  return id || null;
+}
+
+export function loadJson<T>(key: string | null, revive: Reviver<T>, fallback: T): T {
+  const store = getStore();
+  if (!key || !store) {
+    return fallback;
+  }
+
+  try {
+    const raw = store.getItem(key);
+    if (!raw) {
+      return fallback;
+    }
+
+    return revive(JSON.parse(raw) as unknown) ?? fallback;
+  } catch {
+    return fallback;
+  }
+}
+
+export function saveJson(key: string | null, value: unknown, isEmpty: (value: unknown) => boolean): void {
+  const store = getStore();
+  if (!key || !store) {
+    return;
+  }
+
+  try {
+    if (isEmpty(value)) {
+      store.removeItem(key);
+      return;
+    }
+
+    store.setItem(key, JSON.stringify(value));
+  } catch {
+    // localStorage quota / serialization errors are non-critical for this UI.
+  }
+}
+
+export function loadStringSet(key: string | null): Record<string, true> {
+  return loadJson<Record<string, true>>(
+    key,
+    (raw) => {
+      if (!Array.isArray(raw)) {
+        return null;
+      }
+
+      const result: Record<string, true> = {};
+      for (const value of raw) {
+        if (typeof value === 'string' && value.length > 0) {
+          result[value] = true;
+        }
+      }
+
+      return result;
+    },
+    {},
+  );
+}
+
+export function saveStringSet(key: string | null, value: Record<string, true>): void {
+  const ids = Object.keys(value);
+  saveJson(key, ids, () => ids.length === 0);
+}