Authorize tenant-engine guardrail read and set actions

FLEX-WP-0014. Package tenant-engine.write-api.mutate v1 now carries
nine actions: tenant.guardrail.read and tenant.guardrail.set on
resource type guardrail, verbatim from tenant-engine's mapping.

The read/write split is used now: flex-auth may read ceilings and is
denied action_not_granted on set; tenant-engine may do both. 17/17
Rego tests and 23/23 fixtures pass. Live e2e against a real
tenant-engine FlexAuthWriteAuthorizer matches.

In source only; production still serves the seven-action 9320df39 pin.

examples/tenant-engine/protected_system_manifest.yaml

@@ -23,6 +23,15 @@ resource_types:
       - Audit
     metadata:
       description: A tenant's plan/subscription assignment (by reference id).
+  - name: guardrail
+    scope_level: Resource
+    planes:
+      - Policy
+      - Audit
+    metadata:
+      description: >-
+        A tenant's resolved ceiling (spend, seats, and similar limits) plus
+        the provenance of that value. Not an entitlement and not a meter.
 actions:
   - name: tenant.create
     capabilities:
@@ -105,6 +114,28 @@ actions:
       - Metadata
     metadata:
       required_context: []
+  - name: tenant.guardrail.read
+    capabilities:
+      - View
+      - Audit
+    planes:
+      - Policy
+      - Audit
+    exposure_modes:
+      - Metadata
+    metadata:
+      required_context: []
+  - name: tenant.guardrail.set
+    capabilities:
+      - EditAny
+      - Audit
+    planes:
+      - Policy
+      - Audit
+    exposure_modes:
+      - Metadata
+    metadata:
+      required_context: []
 caring_profiles:
   - caring-0.4.0-rc2
 metadata: