docs: Clarify allow_client_traits toggle name and behaviour

[khvn26]

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Changes

Contributes to #6739

The allow_client_traits toggle was labelled "Persist traits when using client-side SDK keys", which implied traits would still be used for evaluation but simply not saved. In reality, when this setting is off, traits from client-side SDKs are completely ignored — they are neither persisted nor used for segment evaluation. This is intentional: it's a security boundary that prevents untrusted clients from sending arbitrary traits to gain access to segments they shouldn't match.

This PR clarifies the toggle name and documentation to match the actual behaviour:

• Frontend: Renamed toggle to "Allow client-side SDKs to set traits" with a description explaining that traits are fully ignored and why.
• Security docs: Updated the toggle name reference and expanded the explanation to clarify that traits are not used for evaluation either, not just not persisted.
• Segments docs: Updated the toggle name reference and wording.

How did you test this code?

Verified the changes visually.

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Project	Deployment	Actions	Updated (UTC)
docs	Ready	Preview, Comment	Feb 25, 2026 2:08pm

2 Skipped Deployments

Project	Deployment	Actions	Updated (UTC)
flagsmith-frontend-preview	Ignored		Feb 25, 2026 2:08pm
flagsmith-frontend-staging	Ignored		Feb 25, 2026 2:08pm

[github-actions]

Docker builds report

Image	Build Status	Security report
ghcr.io/flagsmith/flagsmith-api-test:pr-6782	Finished ✅	Skipped
ghcr.io/flagsmith/flagsmith-e2e:pr-6782	Finished ✅	Skipped
ghcr.io/flagsmith/flagsmith-api:pr-6782	Finished ✅	Results ✅
ghcr.io/flagsmith/flagsmith-private-cloud:pr-6782	Finished ✅	Results ✅
ghcr.io/flagsmith/flagsmith:pr-6782	Finished ✅	Results ✅
ghcr.io/flagsmith/flagsmith-frontend:pr-6782	Finished ✅	Results ✅

[matthewelwell]

This looks good to me, and reflects the behaviour I expected from the attribute. We should evaluate the situation and approach for ensuring the logic in the Edge API matches this before merging this though I think?