Follow up to: #3582504 **Description:** Conditional subcontext currently includes all conditional children when no AI provider/model is configured. This can unexpectedly expand token usage and makes conditional behavior observable even though the provider-dependent selection mechanism is unavailable. Before RC1, conditional subcontext should require an explicitly configured AI Context provider/model. Users should not be able to newly select conditional subcontext without a provider/model, and the UI should clearly explain why the option is unavailable with a link to the global AI Context settings page. The current AI provider dropdown does not expose a “no provider” option and may visually fall back to AI core’s default provider behavior. For now, the settings form should still defensively handle an empty provider/model value in case the AI core element changes later or an empty value is submitted programmatically. If provider/model is empty, conditional subcontext should be ignored rather than included by default. If a provider/model is configured but provider selection or execution fails, conditional children should be skipped deterministically. **Scope:** - Do not allow conditional subcontext authoring when no AI Context provider/model is configured. - Update the context item UI to show conditional subcontext as unavailable without provider/model and link to global settings. - Update the global settings page to warn users when conditional subcontext items depend on the configured provider/model. - Defensively validate against clearing provider/model while published conditional subcontext items exist, even though the current provider dropdown does not expose a “no provider” option. - Update `AiContextSubcontextResolver` so no-provider behavior skips conditional children instead of including all of them. - Ensure configured provider failures are deterministic and skip conditional children. - Add/update documentation and tests. **Acceptance criteria:** - Conditional subcontext cannot be newly selected when no provider/model is configured for AI Context. - Existing conditional subcontext items are not silently converted, but are clearly described as ignored until a provider/model is configured. - The context item form links to the global settings page where provider/model can be configured. - The settings page warns when published conditional subcontext items depend on the provider/model. - If provider/model becomes empty through a future UI change or programmatic submission, validation prevents clearing it while published conditional subcontext items exist. - No-provider conditional subcontext behavior does not include conditional children. - Provider failure behavior is deterministic, documented, and skips conditional children. - Tests cover no-provider behavior, provider failure behavior, UI provider gating, and defensive settings validation. **AI usage disclosures:** - [x] AI Assisted Issue - [x] AI Generated Code