feat: support batch adding accounts via JSON token files

[JPClaw12]

Summary

This PR adds a batch account import flow from JSON token files in the web dashboard.

Changes

• add a new "Batch Add via JSON Token File" action in the header
• support importing JSON in multiple formats: a single token object, an array of token objects, and the existing export format { accounts: [...] }
• normalize token fields from either token / access_token and refreshToken / refresh_token
• reuse the existing /auth/accounts/import endpoint for batch import
• show importing state and import result message in the UI
• refresh the account list after successful import
• add i18n strings for the new batch import button and loading state

Validation

• npm run build passed
• npm test still has unrelated existing failures:
  • src/tls/__tests__/setup-curl-arch.test.ts (spawnSync npx ENOENT)
  • packages/electron/__tests__/build.test.ts (missing packages/electron/dist-electron/server.mjs output path)

Attribution

• Vibe Idea by : JPClaw12
• Coding by : GPT-5.4 High

Request

@icebear0828 Please help review and merge if the implementation looks good.

[icebear0828]

Thanks for the contribution! 🙏

We already have JSON import/export built into the account list section (AccountImportExport component) — it supports both { accounts: [...] } and raw array formats, with multi-file selection.

The field normalization part (access_token / refresh_token compat) is a nice idea though — we'll incorporate that into the existing import flow.

Closing this as duplicate, but appreciate the effort!

[icebear0828]

Update: reopened — sorry about the premature close.

The duplicate header button we'll skip, but the field normalization (access_token → token, refresh_token → refreshToken) in normalizeImportEntry is useful. We already have a JSON import/export flow in the account list (AccountImportExport component), so we'd like to merge that normalization logic into the existing importAccounts instead of adding a second entry point.

Could you update the PR to:

1. Keep the normalizeImportEntry / parseImportAccounts logic in use-accounts.ts
2. Apply it inside the existing importAccounts function
3. Drop the Header button / importTokenJsonFile / new i18n keys

That way we get the format compatibility improvement without duplicating the import UI. Let us know if you'd like us to handle this instead!