feat(analytics-browser): add shouldTrackSubmit for custom form validation

[Mercy811]

Summary

Adds a new shouldTrackSubmit callback option to form interaction config to control when [Amplitude] Form Submitted events are tracked. This is particularly useful for forms with the novalidate attribute where teams want full control over validation before tracking. Previously, [Amplitude] Form Submitted was fired on every form submit event regardless of form validation state.

Checklist

• Does your PR title have the correct title format?
• Does your PR have a breaking change?:

---

Note

Introduces configurable form submit gating.

• Adds FormInteractionsOptions.shouldTrackSubmit type in analytics-core and exports it; updates BrowserConfig/AutocaptureOptions to allow formInteractions: boolean | FormInteractionsOptions.
• Implements getFormInteractionsConfig and integrates it in the form interaction plugin to conditionally track [Amplitude] Form Submitted (checks SubmitEvent, handles errors, keeps [Amplitude] Form Started logic unchanged).
• Extends tests for default-tracking and form interaction plugin covering allow/deny/error paths; updates test server page to novalidate and demonstrates custom validation usage; minor experiment test adds version assertion.

^{Written by Cursor Bugbot for commit b6cda67. Configure here.}

[Mercy811]

bugbot run

[macroscopeapp]

Add FormInteractionTracking gating of [Amplitude] Form Submitted via DefaultTrackingOptions.formInteractions.shouldTrackSubmit and expose FormInteractionsOptions types

Introduce a typed FormInteractionsOptions with shouldTrackSubmit(event) and wire it into the form interaction enrichment plugin, including a getFormInteractionsConfig helper and updated event handler signatures; add tests and export types.

🖇️ Linked Issues

Addresses AMP-147416 by allowing invalid or empty submissions to be excluded from “Form Submitted” via a callback; contributes to the ongoing maintenance tracked under AMP-95968 and AMP-93905.

📍Where to Start

Start in the plugin setup and submit handler in packages/analytics-browser/src/plugins/form-interaction-tracking.ts, then review the config helper in packages/analytics-browser/src/default-tracking.ts.

---

Macroscope summarized b6cda67.

[Mercy811]

bugbot run

[Mercy811]

bugbot run

[Mercy811]

bugbot run

[cursor]

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

[daniel-graham-amplitude]

Lgtm!