spr migrated books, and tester

artery/__init__.py

@@ -16,10 +16,15 @@ Hierarchy (simple → complex):
     └── Stateless API connector
         (e.g., Jira client, Slack client)
 
+
+    Shunt ─── Fake connector for testing
+              (e.g., mercadopago shunt with configurable responses)
+
 Components:
     - veins/     Stateless connectors (core/ + api/)
     - pulses/    Composed: Vein + Room + Depot
     - plexuses/  Full applications with frontend
+    - shunts/    Fake connectors for testing (configurable responses)
     - rooms/     Environment configs
     - depots/    Data storage
 
@@ -31,6 +36,12 @@ Differences:
     | Frontend   | Optional test UI  | None (uses vein)  | Required full frontend    |
     | Webhooks   | No                | No                | Yes                       |
     | Deploy     | With soleprint    | With soleprint    | Self-contained (docker)   |
+
+    | Aspect     | Shunt                                                         |
+    |------------|---------------------------------------------------------------|
+    | Purpose    | Fake/mock external service for testing                        |
+    | Frontend   | Config UI to set responses                                    |
+    | Deploy     | With soleprint (replaces real vein during testing)            |
 """
 
 from . import veins