fix: rename Architecture to How It Works with Local Mode description

- Change '## Architecture' to '## How It Works'
- Change 'Local Mode' to 'Local Mode Architecture'
- Update description to 'Zero auth, single-tenant, perfect for personal use'

Author: m1rl0k

README.md

@@ -123,10 +123,10 @@ Skills teach agents to prefer Context-Engine MCP tools over grep/find/cat for co
 
 ---
 
-## Architecture
+## How It Works
 
-### Local Mode
-*Development and single-user deployment*
+### Local Mode Architecture
+*Zero auth, single-tenant, perfect for personal use*
 
 ```mermaid
 flowchart TB