[management,proxy] Serve guardrail allowlists of declared model ids (#7389)

After #7221, guardrail allowlists built from a path-style provider's declared
model ids (Bedrock, Vertex) stopped working: the raw region/version form was
compared against the parser's canonical id, so the agent config advertised an
empty model list and requests for the allowlisted model were refused.

Make every allowlist compare provider-aware, keyed on the destination
provider's catalog id: the agent config, the policy gate, and the synthesized
proxy allowlists match an entry on both its verbatim and canonical form —
Bedrock's strip only under bedrock_api, Vertex's only under vertex_ai_api,
verbatim everywhere else, so a plain provider's suffixed entries never widen.
The router's claim compare learns the Vertex @version strip.

New e2e, realstore, and unit tests reproduce both regressions and pin the fix.

e2e/harness/agentnetwork.go

@@ -100,6 +100,15 @@ func (c *Combined) SetProviderEnabled(ctx context.Context, id string, enabled bo
 	return err
 }
 
+// GetAgentConfig returns the caller-scoped self-service connection config —
+// the answer the dashboard's "Connect Agent" view renders for the PAT's user.
+// Providers appear only when the caller's own groups intersect an enabled
+// policy's source groups, so tests must place the PAT user into the policy's
+// source group first (via the Users API auto-groups).
+func (c *Combined) GetAgentConfig(ctx context.Context) (api.AgentNetworkAgentConfig, error) {
+	return anRequest[api.AgentNetworkAgentConfig](ctx, c, http.MethodGet, "/api/agent-network/agent-config", nil)
+}
+
 // CreatePolicy creates an agent-network policy.
 func (c *Combined) CreatePolicy(ctx context.Context, req api.AgentNetworkPolicyRequest) (api.AgentNetworkPolicy, error) {
 	return anRequest[api.AgentNetworkPolicy](ctx, c, http.MethodPost, "/api/agent-network/policies", req)