deploy(fc-chat): roll user-bubble prompt-leak fix v20260614-bubblefix-37f57b0

Stored/displayed user message is now the raw prompt; injected scaffolding
(mood contract + guidance + memory) goes to the model via ragContext as a
system message and is captured in RagContextSnapshot for debug.
FlowerCore.Chat 37f57b0 + FlowerCore.Common 4d741b3.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/fc-chat/fc-chat.yaml

@@ -123,7 +123,7 @@ spec:
         fsGroupChangePolicy: OnRootMismatch
       containers:
         - name: chat-web
-          image: localhost/fc-chat-web:v20260614-moodsignal-a606892
+          image: localhost/fc-chat-web:v20260614-bubblefix-37f57b0
           imagePullPolicy: Never
           ports:
             - name: http