Add grounded unified search answers and live verification

docs/modules/advisory-ai/unified-search-architecture.md

@@ -56,6 +56,12 @@ flowchart LR
   - grounding score
   - action suggestions
 - If LLM is unavailable or blocked by quota, deterministic output is still returned.
+- Query responses may also include a deterministic `contextAnswer` envelope for answer-first search UX:
+  - `status`: `grounded` | `clarify` | `insufficient`
+  - `code`, `summary`, `reason`, `evidence`
+  - bounded `citations`
+  - bounded follow-up `questions`
+- The answer envelope is additive and optional so older clients remain compatible.
 
 ## Data Flow
 
@@ -95,6 +101,13 @@ sequenceDiagram
 - `POST /v1/search/synthesize`
 - `POST /v1/search/index/rebuild`
 
+`POST /v1/search/query` response notes:
+- Entity cards remain the primary retrieval payload.
+- `contextAnswer` is the preferred answer-first surface for Web self-serve UX when present.
+- Live local verification currently covers the Doctor/knowledge path after the documented rebuild order:
+  1. `POST /v1/advisory-ai/index/rebuild`
+  2. `POST /v1/search/index/rebuild`
+
 OpenAPI contract presence is validated by integration test:
 - `UnifiedSearchEndpointsIntegrationTests.OpenApi_Includes_UnifiedSearch_Contracts`