Summary

• Fixes a race condition where browser sessions destroyed via webhook are never billed against the team's subscription
• The webhook path passes subscription_id: undefined (meaning "look it up"), but queueBillingOperation coerces it to null before serializing to Redis. When supaBillTeam deserializes, null === undefined is false, so fetch_subscription is set to false. The RPC gets sub_id=null with fetch_subscription=false — credits are logged in credit_usage but never deducted from the subscription balance
• Adds an explicit fetch_subscription boolean to BillingOperation and GroupedBillingOperation, captured before the undefined→null coercion, propagated through grouping, and passed into supaBillTeam

Test plan

• Verify existing browser sessions destroyed via user DELETE still bill correctly (subscription_id present, fetch_subscription=false)
• Verify browser sessions destroyed via webhook now bill correctly (subscription_id=null, fetch_subscription=true → RPC looks up subscription)
• Confirm credit_usage rows from webhook destruction now have a non-null subscription_id
• Check dashboard reflects accurate credit usage for teams using browser sessions

Summary by cubic

Fixes a billing gap where webhook-destroyed browser sessions were logged but not charged by preserving the intent to fetch a subscription through Redis queuing and batching. Ensures bill_team_6 receives the correct fetch_subscription signal so credits are deducted.

• Bug Fixes
  • Added an explicit fetch_subscription boolean to BillingOperation and GroupedBillingOperation, captured before the undefined→null coercion, propagated during grouping (group flag becomes true if any op needs lookup), and passed into supaBillTeam.
  • Updated supaBillTeam to respect the preserved fetch_subscription flag even when subscription_id is null, and pass it through to the RPC without an implicit fallback that could override the flag.

^{Written for commit b4db2ac. Summary will update on new commits.}