docs: establish FraudShield constitution v1.0.0

6 core principles: Security-First, Explainability, Test-First,
Observability, Data Privacy by Design, Simplicity (YAGNI).
Includes Security & Compliance, Development Workflow, and Governance sections.

.specify/workflows/workflow-registry.json

@@ -0,0 +1,13 @@
+{
+  "schema_version": "1.0",
+  "workflows": {
+    "speckit": {
+      "name": "Full SDD Cycle",
+      "version": "1.0.0",
+      "description": "Runs specify \u2192 plan \u2192 tasks \u2192 implement with review gates",
+      "source": "bundled",
+      "installed_at": "2026-05-11T22:30:52.738244+00:00",
+      "updated_at": "2026-05-11T22:30:52.738254+00:00"
+    }
+  }
+}