Benjamin Lu 815be49112 fix: keep begin_checkout user_id reactive in subscription flows (#8726) ...

## Summary

Use reactive `userId` reads for `begin_checkout` telemetry so delayed
auth state updates are reflected at event time instead of using a stale
snapshot.

## Changes

- **What**: switched subscription checkout telemetry paths to
`storeToRefs(useFirebaseAuthStore())` and read `userId.value` when
dispatching `trackBeginCheckout`.
- **What**: added regression tests that mutate `userId` after setup /
after checkout starts and assert telemetry uses the updated ID.

## Review Focus

- Verify `PricingTable` and `performSubscriptionCheckout` still emit
exactly one `begin_checkout` event per action, with `checkout_type:
change` and `checkout_type: new` in their respective paths.
- Verify the new tests would fail with stale store destructuring
(manually validated during development).

## Screenshots (if applicable)

N/A

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8726-fix-keep-begin_checkout-user_id-reactive-in-subscription-flows-3006d73d365081888c84c0335ab52e09)
by [Unito](https://www.unito.io)

2026-02-09 02:01:23 -08:00

..

components

fix: keep begin_checkout user_id reactive in subscription flows (#8726)

2026-02-09 02:01:23 -08:00

composables

fix: route gtm through telemetry entrypoint (#8354)

2026-02-07 01:08:48 -08:00

constants

Feat/workspaces 6 billing (#8508)

2026-02-06 20:52:53 -08:00

utils

fix: keep begin_checkout user_id reactive in subscription flows (#8726)

2026-02-09 02:01:23 -08:00