fix: butler audit critical fixes — pain detection, proposal trigger, URI + data flow

5 fixes from focused audit:
- Connect analyze_for_pain_signals() to post_conversation_hook (pain points now auto-created)
- Add "generate solution" button in InsightsSection for high-confidence pain points (>=0.7)
- Fix Memory URI mismatch: viking://agents/ → viking://agent/ (singular)
- Remove duplicate .then() chain in useButlerInsights (was destructuring undefined)
- Update stale director.rs doc comment (multi-agent now enabled by default)

desktop/src/components/ButlerPanel/index.tsx

@@ -37,7 +37,7 @@ export function ButlerPanel({ agentId }: ButlerPanelProps) {
         <h3 className="text-sm font-semibold text-gray-900 dark:text-gray-100 mb-2">
           我最近在关注
         </h3>
-        <InsightsSection painPoints={painPoints} />
+        <InsightsSection painPoints={painPoints} onGenerate={refresh} />
       </div>
 
       {/* Proposals section */}