docs(readme): update assistant roster, prompt layers, repo structure

- Update assistant lists (added Shawn, Watson, David, CASE, AWS SA; modified Scotty/Harper roles)
- Reflect new architecture layers: Tool Prompt Snippets and Shared Context
- Align repository structure diagram with current filesystem layout

docs/personal/team.md

@@ -153,7 +153,7 @@ All nine personal assistants share a **unified Neo4j graph database** with the W
 - **Cross-domain relationships:** Connecting personal life, work, and engineering
 - **80 total node types** with uniqueness constraints and performance indexes
 
-**Canonical schema:** `docs/neo4j-unified-schema.md`
+**Canonical schema:** `docs/tools/neo4j/unified-schema.md`
 **Integration template:** `neo4j-prompt-section.md`
 **Init script:** `utils/neo4j-schema-init.py`
 
@@ -199,7 +199,7 @@ Assistants execute Neo4j queries via MCP (Model Context Protocol):
 ```
 prompts/personal/
 ├── Team.md                      # This file - team overview
-├── neo4j-schema.md              # Legacy schema (see docs/neo4j-unified-schema.md)
+├── neo4j-schema.md              # Legacy schema (see docs/tools/neo4j/unified-schema.md)
 ├── neo4j-prompt-section.md      # Integration template
 ├── watson-system-prompt.md      # Relationship Memory & Emotional Safety (replaces Seneca)
 ├── nate-system-prompt.md        # Travel & Adventure