## What does this PR do?
Adds infrastructure to track impersonation context in booking audit records and displays it in the UI. When an admin impersonates another user and performs booking actions, the audit system now:
- Records the **admin** as the actor (who actually performed the action)
- Stores the **impersonated user's UUID** in a separate `context` field
- Displays **"Impersonated By"** in the booking logs UI when viewing audit details
This separation ensures audit trail integrity (the admin is accountable) while preserving full context about whose account was being used.
### Changes
- Added `uuid` to `impersonatedBy` session object for actor identification
- Added `uuid` to top-level `User` type in next-auth types for session enrichment
- Added `context Json?` field to `BookingAudit` Prisma model
- Added `BookingAuditContextSchema` for type-safe context handling with `actingAsUserUuid` field
- Updated producer service interface and implementation to pass context through all queue methods
- Updated consumer service to persist context to database
- Updated repository to store and fetch context in BookingAudit records
- Added `impersonatedBy` field to `EnrichedAuditLog` type in `BookingAuditViewerService`
- Added `enrichImpersonationContext` method to resolve impersonated user details
- Updated booking logs UI to display "Impersonated By" in expanded details
- Added `impersonated_by` translation key
Link to Devin run: https://app.devin.ai/sessions/3f1252527aef4ead9401bdf055c0817b
Requested by: hariom@cal.com (@hariombalhara)
## Mandatory Tasks (DO NOT REMOVE)
- [x] I have self-reviewed the code (A decent size PR without self-review might be rejected).
- [x] I have updated the developer docs in /docs if this PR makes changes that would require a [documentation change](https://cal.com/docs). N/A - internal infrastructure change
- [ ] I confirm automated tests are in place that prove my fix is effective or that my feature works.
## How should this be tested?
1. Verify type checks pass: `yarn type-check:ci --force`
2. Verify existing audit tests still pass: `TZ=UTC yarn test`
3. To fully test impersonation context display:
- Have an admin impersonate a user
- Perform a booking action (create, cancel, reschedule)
- Navigate to the booking's audit logs
- Expand the details for the action
- Verify "Impersonated By" row appears showing the impersonated user's name
- Verify the BookingAudit record has:
- `actorId` pointing to the admin's AuditActor
- `context` containing `{ actingAsUserUuid: "<impersonated-user-uuid>" }`
## Human Review Checklist
- [ ] Verify the `context` field schema design is appropriate for future extensibility
- [ ] Confirm the `uuid` addition to User type in next-auth doesn't break existing auth flows
- [ ] Check that the optional `context` parameter doesn't break existing queue method callers
- [ ] Verify no migration file is needed (or if squashing is handled separately)
- [ ] Verify the UI displays "Impersonated By" correctly when impersonation context is present
- [ ] Confirm `enrichImpersonationContext` handles edge cases (null context, invalid context, deleted user)
## Checklist
- [x] My code follows the style guidelines of this project
- [x] I have commented my code, particularly in hard-to-understand areas
- [x] I have checked if my changes generate no new warnings
