[SPIKE]: Clarify user identification and access enablement for feature flags

**Background / Problem**

We need to enable specific features for selected users using FFs. While enabling the Officers info for early adopters (refer to https://app.zenhub.com/workspaces/entities---olga-65af15f59e89f5043c2911f7/issues/gh/bcgov/entity/31549) we tried to identify users in LaunchDarkly and modify feature flags using user keys/tokens. However, this approach is not consistently successful.

Some users are missing from the LaunchDarkly user list, and identification appears to depend on how users log in (BCeID vs BC Service Card). In certain cases, a user ID is required, while in others the LaunchDarkly key/token can be retrieved. This inconsistency makes it unclear what information is required from users to correctly configure access.

Additionally, while feature access can be enabled at the organization level, more granular, per-user access may still be required.

**Goals:**

- [ ] Understand how users are identified in LaunchDarkly across different login flows
- [ ] Determine why some users appear in LaunchDarkly and others do not
- [ ] Identify what identifiers (user ID, IDIR, key, token, organization ID, etc.) are required to enable feature flags reliably
- [ ] Define a clear, repeatable process for enabling access for selected users