fix(webapp): use prisma writer for read-after-write of triggered run friendlyId

Switch the two read-after-write taskRun lookups (POST /api/v1/sessions
and POST /api/v1/sessions/:s/end-and-continue) from $replica back to
prisma. Both reads happen immediately after triggering a run on the
writer; replica lag would null the result and turn a successful create
into a 500, or fall back to leaking the internal cuid in the
end-and-continue response.

Author: ericallam

apps/webapp/app/routes/api.v1.sessions.$session.end-and-continue.ts

@@ -4,7 +4,7 @@ import {
   type EndAndContinueSessionResponseBody,
 } from "@trigger.dev/core/v3";
 import { z } from "zod";
-import { $replica } from "~/db.server";
+import { $replica, prisma } from "~/db.server";
 import { logger } from "~/services/logger.server";
 import { swapSessionRun } from "~/services/realtime/sessionRunManager.server";
 import { resolveSessionByIdOrExternalId } from "~/services/realtime/sessions.server";
@@ -107,9 +107,12 @@ const { action, loader } = createActionApiRoute(
         reason,
       });
 
-      // The swap stored a TaskRun.id (cuid) in `currentRunId`; surface
-      // the friendlyId for parity with the rest of the public API.
-      const run = await $replica.taskRun.findFirst({
+      // Read-after-write: the swap just triggered (or claimed) the
+      // run on the writer, so read it from `prisma` rather than
+      // `$replica`. A replica miss here would silently fall back to
+      // returning the internal cuid, which the public API contract
+      // says is a friendlyId.
+      const run = await prisma.taskRun.findFirst({
         where: { id: result.runId },
         select: { friendlyId: true },
       });

apps/webapp/app/routes/api.v1.sessions.ts

@@ -174,9 +174,10 @@ const { action } = createActionApiRoute(
         reason: isCached ? "continuation" : "initial",
       });
 
-      // The newly triggered run's friendlyId, looked up via Prisma — we
-      // need the friendly form for the wire response.
-      const run = await $replica.taskRun.findFirst({
+      // Read-after-write: the run was just triggered in this request,
+      // so go to the writer rather than $replica. Replica lag here
+      // would null this out and turn a successful create into a 500.
+      const run = await prisma.taskRun.findFirst({
         where: { id: ensureResult.runId },
         select: { friendlyId: true },
       });