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/MemorySection.tsx

@@ -20,7 +20,7 @@ export function MemorySection({ agentId }: MemorySectionProps) {
     if (!agentId) return;
 
     setLoading(true);
-    listVikingResources(`viking://agents/${agentId}/memories/`)
+    listVikingResources(`viking://agent/${agentId}/memories/`)
       .then((entries) => {
         setMemories(entries as MemoryEntry[]);
       })