feat: Enhance Slack import and memory promotion rules to better capture multi-channel, multi-year contributions and improve user role identification

knowledge/agent-memory-rules.md

@@ -42,6 +42,7 @@ Examples:
 - confirmed version, dependency, or rollout facts tied to current work
 - corrections to previously stored project context
 - repeated named people with stable roles or communication relevance
+- repeated named people with multi-channel, multi-year, or high-signal technical/process involvement even when the exact formal role is still unknown
 
 ---
 
@@ -106,6 +107,12 @@ Use these files for:
 - keeping named stakeholders recognizable across sessions
 - storing stable communication or responsibility context per person
 
+When the role is not explicit, store:
+
+- where the person tends to appear
+- what kinds of topics they influence
+- how they affect approvals, scope, debugging, or communication
+
 ### `ai/context/decisions/*.md`
 
 Use for explicit confirmed decisions with ongoing impact.