Fix/no suspense

[leonace924]

Add strictNoSuspense TypeScript option for safer useTranslation usage

Fixes #1896

Description

When using useSuspense: false, forgetting to check ready before accessing t causes i18n keys to render on the page. This PR adds an optional TypeScript setting that enforces checking ready before using t.

Usage

// Enable in your i18next.d.ts
declare module 'i18next' {
  interface CustomTypeOptions {
    strictNoSuspense: true;
  }
}

const result = useTranslation('ns', { useSuspense: false });

result.t('key');  // TypeScript error: t is possibly undefined

if (result.ready) {
  result.t('key');  // OK
}

result.ready && result.t('key');  // Also OK

When useSuspense: true (default) or when strictNoSuspense is not enabled, behavior remains unchanged.

Changes

• Added UseTranslationResponseNotReady, UseTranslationResponseReady, and UseTranslationResponseStrict types to index.d.ts
• Added overloads to useTranslation that return discriminated union when useSuspense: false and strictNoSuspense: true
• Added test suite in test/typescript/strict-no-suspense/

Checklist

• only relevant code is changed (make a diff before you submit the PR)
• run tests npm run test
• tests are included
• commit message and code follows the Developer's Certification of Origin

Checklist (for documentation change)

• only relevant documentation part is changed (make a diff before you submit the PR)
• motivation/reason is provided
• commit message and code follows the Developer's Certification of Origin

Contribution by Gittensor, see my contribution statistics at https://gittensor.io/miners/details?githubId=42954461

[coveralls]

coverage: 97.682%. remained the same
when pulling ea038a4 on leonace924:fix/no-suspense
into 272929c on i18next:master.

[adrai]

if this lands, we need to update the docs, either here or here or both.

[leonace924]

if this lands, we need to update the docs, either here or here or both.

@adrai do i need to update the docs as well?

[adrai]

if this lands, we need to update the docs, either here or here or both.

@adrai do i need to update the docs as well?

if this PR lands, yes - that would be nice

[leonace924]

if this lands, we need to update the docs, either here or here or both.

@adrai do i need to update the docs as well?

if this PR lands, yes - that would be nice

@adrai i will put the PR for docs once this is landed.
When would you review and this can land?

[adrai]

When would you review and this can land?

depends on @marcalexiei or @ahrjarrett