phase 4: drop stale gRPC nomenclature from integration tests

Phase 4 replaced the gateway's authenticated edge listener with a
Connect-Go HTTP/h2c bootstrap that natively serves Connect, gRPC,
and gRPC-Web. Sweep the integration suite so test names, comments,
and helper docs match the new transport posture: rename
TestUserAccount_GetThroughGatewayGRPC to TestUserAccount_GetThroughGatewayEdge,
flip "authenticated gRPC" / "signed gRPC" / "gateway gRPC" comments
to "authenticated edge", and align testenv doc strings.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

integration/session_revoke_test.go

@@ -11,7 +11,7 @@ import (
 )
 
 // TestSessionRevoke_SubsequentRequestsRejected revokes the caller's
-// session through the user surface (signed gRPC end-to-end) and
+// session through the user surface (signed authenticated-edge end-to-end) and
 // asserts that subsequent authenticated calls bound to that session
 // are rejected by gateway.
 func TestSessionRevoke_SubsequentRequestsRejected(t *testing.T) {
@@ -35,7 +35,7 @@ func TestSessionRevoke_SubsequentRequestsRejected(t *testing.T) {
 		t.Fatalf("pre-revoke call failed: %v", err)
 	}
 
-	// Revoke own session through signed gRPC.
+	// Revoke own session through signed authenticated-edge call.
 	revokePayload, err := transcoder.RevokeMySessionRequestToPayload(&usermodel.RevokeMySessionRequest{
 		DeviceSessionID: sess.DeviceSessionID,
 	})