Follow up to: #3582504 **Description:** The `ai_context.agents` config is part of the stable API surface. It currently stores scope subscriptions and inclusion overrides, but not per-agent injection limits. `AiContextRequestFactory::fromAgent()` always uses `max_global_items`, `max_items`, and `max_tokens` from the general settings, and hardcoded `minimal` selection mode. **Scope:** - Add optional `max_global_items`, `max_items`, `max_tokens`, and `selection_mode` keys to `ai_context.agents` config schema. - Add fields to the agent context configuration form. - Update `AiContextRequestFactory::fromAgent()` to use per-agent values when present and fall back to general default settings otherwise. - Ensure invalid/empty values fall back safely. - Add tests for schema, form persistence, and request factory behavior. **Acceptance criteria:** - Each agent can override max global items, max items, max tokens, and selection mode. - Existing agent config without these keys continues to work. - General default settings remain the fallback. - Tests prove per-agent overrides affect built `AiContextRequest` objects. **AI usage disclosures:** - [x] AI Assisted Issue - [x] AI Generated Code