Merge branch 'coach/wp7-continue' into release/v1.39.4

# Conflicts:
#	src/lib/ai/coach/turn/pipeline.ts
#	src/lib/ai/coach/turn/provenance.ts

docs/api/openapi.yaml

@@ -50407,6 +50407,11 @@ components:
           description: v1.39.4 — the answer was forced at the round cap while the Coach still wanted to read. Absent otherwise.
           type: boolean
           const: true
+        continuationOf:
+          description: "v1.39.4 — this reply continues an answer that was forced at the round cap (the `continue` chip): the id of
+            that earlier assistant message. A continuation offers no further `continue` chip. Absent otherwise."
+          type: string
+          maxLength: 64
       required:
         - windows
         - metrics