[e2e] Add management-side agent-network scenarios (Pillar 2)

Port the API-driven agent-network scenarios from the bash suites to Go,
sharing one combined server per package run (TestMain) with each test
owning its resource cleanup. Drives the /api/agent-network/* endpoints
through the shared REST client's NewRequest primitive with the generated
api types.

Scenarios:
- provider lifecycle (create/get/list/delete + 404 after delete)
- provider validation (missing api_key, unknown catalog id → 4xx)
- settings collection-toggle round-trip with cluster/subdomain immutability
- policy window floor (reject <60s enabled limit, accept at 60s)
- consumption read endpoint returns an array

All deterministic and dependency-free (dummy provider keys; no upstream
calls), so they run headless in CI.

e2e/agentnetwork/bootstrap_test.go

@@ -5,32 +5,19 @@ package agentnetwork
 import (
 	"context"
 	"testing"
-	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-
-	"github.com/netbirdio/netbird/e2e/harness"
 )
 
-// TestCombinedBootstrap proves Pillar 1: a combined NetBird server comes up in a
-// container, the /api/setup bootstrap mints an admin PAT with no OIDC, and that
-// PAT authenticates real management API calls through the typed REST client.
+// TestCombinedBootstrap proves Pillar 1: the shared combined server came up and
+// the /api/setup-minted PAT authenticates a real management API call through
+// the typed REST client (the bootstrap itself ran in TestMain).
 func TestCombinedBootstrap(t *testing.T) {
-	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Minute)
-	defer cancel()
+	ctx := context.Background()
 
-	srv, err := harness.StartCombined(ctx)
-	require.NoError(t, err, "combined server must build and start")
-	t.Cleanup(func() {
-		_ = srv.Terminate(context.Background())
-	})
+	require.NotEmpty(t, srv.PAT, "TestMain must have minted an admin PAT")
 
-	pat, err := srv.Bootstrap(ctx)
-	require.NoError(t, err, "/api/setup must mint an admin PAT")
-	require.NotEmpty(t, pat, "PAT must be non-empty")
-
-	// The PAT must authenticate a real management API call through the client.
 	users, err := srv.API().Users.List(ctx)
 	require.NoError(t, err, "authenticated Users.List must round-trip")
 	require.NotEmpty(t, users, "the bootstrapped account must have at least one user")