feat(webapp): let the deployment S2 client endpoints be overridden

The S2 SDK honours only endpoints passed to its constructor — S2Environment.parse()
is an opt-in helper the webapp never called — so the deployment event log always
targeted hosted S2 and could not be pointed at the local s2-lite emulator. Realtime
already has this knob (REALTIME_STREAMS_S2_ENDPOINT); deployments did not, which made
a deployed-run end-to-end test impossible locally.

S2_ACCOUNT_ENDPOINT and S2_BASIN_ENDPOINT are optional and unset in production, where
the SDK's hosted defaults continue to apply.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: d-cs

apps/webapp/app/env.server.ts

@@ -79,6 +79,12 @@ const S2EnvSchema = z.preprocess(
       S2_ACCESS_TOKEN: z.string(),
       S2_DEPLOYMENT_LOGS_BASIN_NAME: z.string(),
       S2_DEPLOYMENT_STREAMS_LOCAL: z.string().default("0"),
+      // Override the S2 service endpoints. Unset means the SDK's hosted defaults
+      // (a.s2.dev / {basin}.b.s2.dev). Set both to point deployment event logs at a
+      // local s2-lite (the docker compose `s2` service), which is what makes a
+      // deployed-run e2e possible without hosted S2 credentials.
+      S2_ACCOUNT_ENDPOINT: z.string().optional(),
+      S2_BASIN_ENDPOINT: z.string().optional(),
     }),
     z.object({
       S2_ENABLED: z.literal("0"),

apps/webapp/app/presenters/v3/DeploymentPresenter.server.ts

@@ -13,7 +13,7 @@ import { type User } from "~/models/user.server";
 import { getUsername } from "~/utils/username";
 import { processGitMetadata } from "./BranchesPresenter.server";
 import { VercelProjectIntegrationDataSchema } from "~/v3/vercel/vercelProjectIntegrationSchema";
-import { S2 } from "@s2-dev/streamstore";
+import { createDeploymentS2Client } from "~/v3/s2Client.server";
 import { env } from "~/env.server";
 import { createRedisClient } from "~/redis.server";
 import { tryCatch } from "@trigger.dev/core";
@@ -30,7 +30,7 @@ const s2TokenRedis = createRedisClient("s2-token-cache", {
   clusterMode: env.CACHE_REDIS_CLUSTER_MODE_ENABLED === "1",
 });
 
-const s2 = env.S2_ENABLED === "1" ? new S2({ accessToken: env.S2_ACCESS_TOKEN }) : undefined;
+const s2 = createDeploymentS2Client();
 
 export type ErrorData = {
   name: string;

apps/webapp/app/v3/s2Client.server.ts

@@ -0,0 +1,18 @@
+import { S2 } from "@s2-dev/streamstore";
+import { env } from "~/env.server";
+
+// The SDK honours only endpoints passed to the constructor — `S2Environment.parse()` is an
+// opt-in helper — so the endpoint env vars are read here explicitly. Unset means hosted S2.
+export function createDeploymentS2Client(): S2 | undefined {
+  if (env.S2_ENABLED !== "1") {
+    return undefined;
+  }
+
+  const account = env.S2_ACCOUNT_ENDPOINT;
+  const basin = env.S2_BASIN_ENDPOINT;
+
+  return new S2({
+    accessToken: env.S2_ACCESS_TOKEN,
+    ...(account !== undefined || basin !== undefined ? { endpoints: { account, basin } } : {}),
+  });
+}

apps/webapp/app/v3/services/deployment.server.ts

@@ -23,7 +23,8 @@ import {
 import { FEATURE_FLAG, type FeatureFlagKey } from "../featureFlags";
 import { flags } from "../featureFlags.server";
 import { globalFlagsRegistry } from "../globalFlagsRegistry.server";
-import { AppendInput, AppendRecord, S2 } from "@s2-dev/streamstore";
+import { AppendInput, AppendRecord } from "@s2-dev/streamstore";
+import { createDeploymentS2Client } from "~/v3/s2Client.server";
 import { createRedisClient } from "~/redis.server";
 
 const S2_TOKEN_KEY_PREFIX = "s2-token:read:deployment-event-stream:project:";
@@ -35,7 +36,7 @@ const s2TokenRedis = createRedisClient("s2-token-cache", {
   tlsDisabled: env.CACHE_REDIS_TLS_DISABLED === "true",
   clusterMode: env.CACHE_REDIS_CLUSTER_MODE_ENABLED === "1",
 });
-const s2 = env.S2_ENABLED === "1" ? new S2({ accessToken: env.S2_ACCESS_TOKEN }) : undefined;
+const s2 = createDeploymentS2Client();
 
 const DEPLOY_BUILD_PATH_ENV_FLAG: Partial<Record<RuntimeEnvironmentType, FeatureFlagKey>> = {
   PREVIEW: FEATURE_FLAG.deployBuildPathPreview,