Commit 7a13b1

2026-04-27 19:58:04 lisa: Context Diagram: replace ASCII worked example with mermaid ASCII layout was inaccurate due to text-grid limits. Mermaid flowchart renders the Yourdon-DeMarco notation cleanly and matches existing wiki precedent (C01 Problem-Solving Methodology).

sd/C02/Context Diagram.md ..
@@ 53,28 53,22 @@
	## Worked example: Sales Order System
-	```
-	┌───────────┐
-	│ Managers │
-	└─────┬─────┘
-	│ New Employee ▼ ▲ Employee Lists
-	│ │ Vendor & Product-vendors
-	│ │
-	▼ │
-	┌──────────────────────────────────┐
-	│ │
-	│ ( Sales Order System ) │
-	│ │
-	└──────────────────────────────────┘
-	▲ │ │ ▲
-	│ │ │ │ Order Invoices
-	Updates │ │ Customer │ │
-	Employee│ │ Order & │ │ Order &
-	Product │ │ Order-line │ │ Order-line
-	& Cat. │ ▼ │ │
-	┌──┴────────┐ ┌─────┴──┴─┐
-	│ Employees │ │ Customers │
-	└───────────┘ └───────────┘
+	```mermaid
+	flowchart LR
+	M[Managers]
+	E[Employees]
+	C[Customers]
+	S(("Sales Order<br/>System"))
+
+	M -->|New Employee| S
+	S -->|Employee Lists| M
+	S -->|Vendor & Product-vendors| M
+	E -->|Updates Employee| S
+	E -->|Product & Category| S
+	C -->|Customer details| S
+	C -->|Order & Order-line| S
+	S -->|Order & Order-line| C
+	S -->|Order Invoices| C
	```
	**Read it like this:**