Update Vue and Nuxt component tracking docs: Options API requirement and stale defaults

[s1gr1d]

SDK

JavaScript SDK

Description

Follow-up to getsentry/sentry-javascript#23375.

Nuxt 5 disables Vue's Options API by default
(nuxt/nuxt#35791), which turns app.mixin() into a silent no-op. The SDK records the default
spans through an app.mount() wrap instead; component tracking (trackComponents) still needs
the Options API.

Affected pages:

• https://docs.sentry.io/platforms/javascript/guides/vue/features/component-tracking/
• https://docs.sentry.io/platforms/javascript/guides/nuxt/features/component-tracking/

What to document

• Component tracking needs the Options API. trackComponents (and non-default hooks)
  only work through app.mixin(). The SDK logs a console warning when the mixin is unavailable.
• Nuxt 5 callout. The Options API is off by default there; component spans need
  vue: { optionsApi: true } in nuxt.config.ts. Plain Vue users control it through the
  __VUE_OPTIONS_API__ define in their bundler.
• Default spans work without the Options API. Application Render and the root
  Vue <Root> mount span are always recorded. On Nuxt without the Options API, the root render
  span extends until the page's <Suspense> boundary resolves.
• Fix the default hook set. Both pages say ['activate', 'mount', 'update']; the SDK
  default is ['activate', 'mount'] (packages/vue/src/constants.ts).
• Fix the span op. The Vue page says ui.vue.render; the SDK emits op ui.render with
  origin auto.ui.vue.
• Fix the timeout wording. "Waits for the last component to render" is wrong: debounce
  timers are per component, so late mounts (async components, lazy routes, <Suspense>) do not
  extend the span. It ends with the initial synchronous render.
• Root component is always tracked. hooks apply to the root even with
  trackComponents: false, e.g. hooks: ['update'] alone produces a Vue <Root> ui.update
  span. Undocumented on both pages.

References

• packages/vue/src/tracing.ts, packages/vue/src/constants.ts
• packages/vue/test/integration/mixinRegistration.test.ts (root tracking, hook behavior, late
  children not extending the span)
• dev-packages/e2e-tests/test-applications/vue-3/tests/performance.test.ts (delayed async
  component, both variants)

Suggested Solution

No response

[linear-code]

DOCS-2943