docs(v2): Redis prefix for session keys

[ivanzolotuhin]

Adds the prefix field to the Redis session storage schema

Verified from Flipt's v2 branch source (internal/config/authentication.go):

type AuthenticationSessionStorageRedisConfig struct {
    ...
    Prefix string `json:"prefix" mapstructure:"prefix" yaml:"prefix"`
    Mode   RedisCacheMode `json:"mode" mapstructure:"mode" yaml:"mode"`
}   

[github-actions]

Verdict: comment

The PR adds a prefix row to the Redis session storage config table in overview.mdx, which addresses the prior review's request to keep the reference table consistent with the authentication examples. One issue: the default column is empty even though the PR description states the default is auth:... — the default should be filled in so users know the out-of-box behavior, consistent with how cache.redis.prefix documents its default of "flipt".

docs/v2/configuration/overview.mdx

• minor (L324): The default column is empty for the authentication.session.storage.redis.prefix row, but the PR description states the default is auth:.... Fill in the default value in the table (e.g., auth:) so users know the default behavior without reading the example — consistent with how cache.redis.prefix documents its default of "flipt". If there is genuinely no default (empty string), clarify the PR description which currently claims a default exists.

🤖 Automated review by the Flipt PR review agent.

[ivanzolotuhin]

moved to schema