feat: seed Lariza feature demonstration

Add synthetic fixtures and proposed policy contracts for safely demonstrating future Lariza capabilities.

Assisted-by: Codex: GPT-5.6

.lariza/environments.yaml

@@ -0,0 +1,27 @@
+apiVersion: delivery.lariza.dev/v1alpha1
+kind: EnvironmentSetIntent
+metadata:
+  name: sample-promotion-path
+spec:
+  environments:
+    - name: development
+      tier: development
+      approvals: 0
+    - name: staging
+      tier: staging
+      approvals: 1
+      requiredChecks: [integration-tests]
+    - name: production
+      tier: production
+      approvals: 2
+      disallowSelfApproval: true
+      requiredGroups: [service-owner, operations]
+      requiredChecks: [security-gate, change-window, gitops-ready]
+      freezeWindows:
+        - name: weekend-freeze
+          timezone: Asia/Manila
+          expression: 'Fri 18:00-Mon 08:00'
+      emergencyBypass:
+        requireReason: true
+        requireIncident: true
+        notify: [governance-owners]