Match the Bedrock e2e inference profile to the configured region

The matrix hardcoded the us. cross-region inference profile while the
upstream host follows AWS_REGION, so any non-US region made Bedrock
reject every request with 'The provided model identifier is invalid' —
including the allowlisted call in TestModelAllowlistEnforced, which
asserts a 200. Derive the profile prefix (us/eu/apac/us-gov) from the
region, default the region to eu-central-1 to match the CI credentials,
and strip whichever prefix was chosen when building the guardrail
allowlist.

e2e/agentnetwork/chat_test.go

@@ -95,17 +95,36 @@ func availableProviders() []providerCase {
 	}
 
 	// Bedrock: path-routed, bearer auth. Model is a cross-region inference
-	// profile id (distinct string from the first-party Anthropic case).
+	// profile id (distinct string from the first-party Anthropic case). The
+	// profile's region prefix must match the endpoint's region family — an
+	// eu.* profile against a us-east endpoint (or vice versa) makes Bedrock
+	// reject the request with "The provided model identifier is invalid".
+	// Defaults pair eu-central-1 with the eu.* profile; AWS_REGION overrides
+	// the region and the prefix follows its family.
 	if k := os.Getenv("AWS_BEARER_TOKEN_BEDROCK"); k != "" {
 		region := os.Getenv("AWS_REGION")
 		if region == "" {
-			region = "us-east-1"
+			region = "eu-central-1"
 		}
-		ps = append(ps, providerCase{name: "bedrock", catalogID: "bedrock_api", upstream: "https://bedrock-runtime." + region + ".amazonaws.com", apiKey: k, model: "us.anthropic.claude-haiku-4-5", kind: harness.WireBedrock})
+		ps = append(ps, providerCase{name: "bedrock", catalogID: "bedrock_api", upstream: "https://bedrock-runtime." + region + ".amazonaws.com", apiKey: k, model: bedrockProfilePrefix(region) + ".anthropic.claude-haiku-4-5", kind: harness.WireBedrock})
 	}
 	return ps
 }
 
+// bedrockProfilePrefix maps an AWS region to its cross-region inference
+// profile prefix: us-east-1 -> us, eu-central-1 -> eu, ap-southeast-1 -> apac,
+// us-gov-west-1 -> us-gov.
+func bedrockProfilePrefix(region string) string {
+	switch {
+	case strings.HasPrefix(region, "us-gov-"):
+		return "us-gov"
+	case strings.HasPrefix(region, "ap-"):
+		return "apac"
+	default:
+		return strings.SplitN(region, "-", 2)[0]
+	}
+}
+
 // providerRequest builds a create request for a matrix provider: enabled, with
 // a uniquely-priced model for body-routed providers and none for the
 // path-routed Vertex (whose model lives in the request path).

e2e/agentnetwork/guardrail_test.go

@@ -21,7 +21,14 @@ import (
 func catalogModel(pc providerCase) string {
 	switch pc.kind {
 	case harness.WireBedrock:
-		return strings.TrimPrefix(pc.model, "us.")
+		// Strip whichever cross-region inference-profile prefix the matrix
+		// picked for the configured AWS region (us., eu., apac., us-gov.).
+		for _, p := range []string{"us-gov.", "apac.", "us.", "eu."} {
+			if strings.HasPrefix(pc.model, p) {
+				return strings.TrimPrefix(pc.model, p)
+			}
+		}
+		return pc.model
 	case harness.WireVertex:
 		return strings.SplitN(pc.model, "@", 2)[0]
 	default:
@@ -35,7 +42,9 @@ func catalogModel(pc providerCase) string {
 func disallowedModel(pc providerCase) string {
 	switch pc.kind {
 	case harness.WireBedrock:
-		return "us.anthropic.claude-opus-4-8"
+		// Same profile prefix as the allowed model so only the model name
+		// differs; the guardrail must deny it before it reaches AWS.
+		return strings.SplitN(pc.model, ".", 2)[0] + ".anthropic.claude-opus-4-8"
 	case harness.WireVertex:
 		return "claude-opus-4-8@20250101"
 	default: