fix: Only allow VM.Standard.E4.Flex and E5.Flex for right-sizing

B1.16 has 16 fixed CPUs but grafana-agent only needs 5 CPU + 30GB.
E4.Flex and E5.Flex can be sized to exactly 3 OCPUs (6 vCPUs) + 30GB.

- Block all other VM.Standard shapes (B1, E2, etc.)
- Only allow E4.Flex and E5.Flex that support flexible sizing
- This enables true right-sizing: 3 OCPUs instead of 16 CPUs

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: haimari

pkg/providers/oci/instancetypes.go

@@ -101,8 +101,19 @@ func (p *InstanceTypeProvider) isAllowedShape(shapeName string) bool {
 		}
 	}
 
-	// Only allow x86-compatible Standard shape families (VM.Standard.E4.Flex, VM.Standard.E5.Flex, etc.)
-	return strings.HasPrefix(shapeName, "VM.Standard")
+	// Only allow specific cost-effective flexible shapes that can be right-sized
+	allowedShapes := []string{
+		"VM.Standard.E4.Flex",  // x86 flexible shape - can be sized exactly for workload
+		"VM.Standard.E5.Flex",  // x86 flexible shape - can be sized exactly for workload
+	}
+	
+	for _, allowedShape := range allowedShapes {
+		if strings.HasPrefix(shapeName, allowedShape) {
+			return true
+		}
+	}
+	
+	return false
 }
 
 // GetDynamicInstanceTypes generates instance types based on pod requirements and NodePool configuration