poc-memory: fix distill placeholder, show link weights in render

- distill.agent: fix {{distill}} → {{nodes}} placeholder so seed
  nodes actually resolve
- render: show link strength values in the links section, sorted
  by strength descending

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

poc-memory/agents/distill.agent

@@ -56,4 +56,4 @@ For each seed node:
 
 ## Seed nodes
 
-{{distill}}
+{{nodes}}