test(webapp): stub the agent proxy's environment lookup, not a Prisma row

The hand-built row stopped satisfying every column the authenticated-environment
mapper reads, so both proxy cases failed. Stubbing the lookup keeps the fixture
independent of the row's columns.

Author: kathiekiwi

apps/webapp/test/dashboardAgentWatchInvestigate.test.ts

@@ -84,11 +84,14 @@ vi.mock("~/models/project.server", () => ({
 }));
 vi.mock("~/db.server", () => ({
   prisma: {},
-  $replica: {
-    runtimeEnvironment: { findFirst: async () => ({ id: "env_1", type: "PRODUCTION" }) },
-  },
+  $replica: {},
   sqlDatabaseSchema: undefined,
 }));
+// Stub the lookup, not the row: the route only reads id and type, while a raw
+// Prisma row has to satisfy every column `toAuthenticated` reads.
+vi.mock("~/models/runtimeEnvironment.server", () => ({
+  findEnvironmentBySlug: async () => ({ id: "env_1", type: "PRODUCTION" }),
+}));
 
 const { action } = await import("~/routes/api.v1.dashboard-agent.watches.$watchId.investigate");
 const { action: inProxyAction } =