Follow up to: #3582494 _**NOTE: Before working on this issue, verify it's still relevant and makes sense.**_ **Description** We need to decide what stable extension points AI Context should expose around context selection so contrib modules and site-specific integrations can inspect, alter, validate, and debug selection without depending on `AiContextSelector` internals. This issue is for discussion and design only. It should decide whether the right extension model is events, plugins, service decoration guidance, or a combination. Questions to resolve: - What selection lifecycle stages need extension points? #3586162 - Should we expose events such as pre-select, post-filter, post-select, and post-render? #3586162 - What data should event payloads include? - How do we expose diagnostics without leaking sensitive context? - How should cacheability metadata be handled? - What follow-up issues should be created? Potential follow-ups: - Add selection lifecycle events #3586162 - Add selection preview/testing UI - Add conflict detection hooks - Add PII redaction hook point - Add multi-scorer selection pipeline [x] AI Assisted Issue