Phase 28-36 body of work

Accumulated since a6f12e2 (Phase 21 Rust port + Phase 27 versioning):

- Phase 36: embed_semaphore on VectorState (permits=1) serializes
  seed embed calls — prevents sidecar socket collisions under
  concurrent /seed stress load
- Phase 31+: run_stress.ts 6-task diverse stress scaffolding;
  run_e2e_rated.ts + orchestrator.ts tightening
- Catalog dedupe cleanup: 16 duplicate manifests removed; canonical
  candidates.parquet (10.5MB -> 76KB) + placements.parquet (1.2MB ->
  11KB) regenerated post-dedupe; fresh manifests for active datasets
- vectord: harness EvalSet refinements (+181), agent portfolio
  rotation + ingest triggers (+158), autotune + rag adjustments
- catalogd/storaged/ingestd/mcp-server: misc tightening
- docs: Phase 28-36 PRD entries + DECISIONS ADR additions;
  control-plane pivot banner added to top of docs/PRD.md (pointing
  at docs/CONTROL_PLANE_PRD.md which lands in next commit)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/vectord/src/rag.rs

@@ -10,6 +10,7 @@ use object_store::ObjectStore;
 use std::sync::Arc;
 
 use aibridge::client::{AiClient, EmbedRequest, GenerateRequest};
+use aibridge::continuation::{generate_continuable, ContinuableOpts, ResponseShape};
 use crate::search::{self, SearchResult};
 use crate::store;
 
@@ -42,7 +43,10 @@ async fn rerank(
         system: None,
         temperature: Some(0.0),
         max_tokens: Some(50),
-        think: None,
+        // Reranker returns a comma-separated int list — pure structured
+        // output, zero benefit from hidden reasoning. Opt out to avoid
+        // the empty-response failure mode Phase 21 catalogued.
+        think: Some(false),
     }).await;
 
     match resp {
@@ -151,19 +155,29 @@ pub async fn query(
         Answer:"
     );
 
-    let gen_resp = ai_client.generate(GenerateRequest {
-        prompt,
-        model: None,
-        system: None,
-        temperature: Some(0.2),
-        max_tokens: Some(512),
-        think: None,
-    }).await?;
+    // Route the answer call through Phase 21's generate_continuable so
+    // a thinking-model empty-response or a mid-JSON truncation self-
+    // repairs instead of silently returning half an answer. Shape is
+    // Text (the answer is prose, not JSON), think is Some(false) to
+    // opt out of hidden reasoning on the hot path. This is the first
+    // production caller of the Phase 21 primitives — see audit finding
+    // "Phase 21 Rust primitives are wired but not CALLED by any
+    // production surface" from 2026-04-21.
+    let mut cont_opts = ContinuableOpts::new("qwen2.5:latest");
+    cont_opts.max_tokens = Some(512);
+    cont_opts.temperature = Some(0.2);
+    cont_opts.shape = ResponseShape::Text;
+    cont_opts.think = Some(false);
+    let outcome = generate_continuable(ai_client, &prompt, &cont_opts).await?;
 
     Ok(RagResponse {
-        answer: gen_resp.text.trim().to_string(),
-        model: gen_resp.model,
+        answer: outcome.text.trim().to_string(),
+        // generate_continuable doesn't surface the model name (sidecar
+        // echoes whatever Ollama loaded). Use the configured tier model
+        // for now; if RAG needs to report the actual resolved model,
+        // the runner can add a post-call ps probe later.
+        model: "qwen2.5:latest".to_string(),
         sources: results,
-        tokens_generated: gen_resp.tokens_generated,
+        tokens_generated: None,
     })
 }