Multi-turn conversation, stop generation, SSE fix, and UI improvements

- Multi-turn context: all council stages now receive conversation history
  (user messages + Stage 3 chairman responses) for coherent follow-ups
- Stop generation: abort streaming mid-request, recover query to input box
- SSE parsing: buffer-based chunking to prevent JSON split across packets
- Atomic storage: user + assistant messages saved together after completion,
  preventing dangling messages on abort
- GFM markdown: tables, strikethrough via remark-gfm plugin + table styles
- Performance: memo user messages and completed assistant messages, only
  re-render the active streaming message
- Model config: gpt-5.2, claude-opus-4.6 as chairman
- Always show input box for multi-turn conversations

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/frontend/src/components/Stage1.jsx b/frontend/src/components/Stage1.jsx
index 071937c..7478876 100644
--- a/frontend/src/components/Stage1.jsx
+++ b/frontend/src/components/Stage1.jsx
@@ -1,5 +1,6 @@
 import { useState } from 'react';
 import ReactMarkdown from 'react-markdown';
+import remarkGfm from 'remark-gfm';
 import './Stage1.css';
 
 export default function Stage1({ responses }) {
@@ -28,7 +29,7 @@ export default function Stage1({ responses }) {
       <div className="tab-content">
         <div className="model-name">{responses[activeTab].model}</div>
         <div className="response-text markdown-content">
-          <ReactMarkdown>{responses[activeTab].response}</ReactMarkdown>
+          <ReactMarkdown remarkPlugins={[remarkGfm]}>{responses[activeTab].response}</ReactMarkdown>
         </div>
       </div>
     </div>