fix(webapp): dashboard run-detail RunPresenter doesn't 'PrismaClient error' on buffered runs

`RunPresenter.call` used `prisma.taskRun.findFirstOrThrow` to load the
run-detail data. For any buffered run (the snapshot lives in Redis,
not PG), the throw fires every page-poll tick and Prisma's `writer`
emits a `PrismaClient error` log line each time — both the run-detail
revalidation poll (~5s) and any Remix `_data` request hit it.

The route loader already catches arbitrary errors from `presenter.call`
and falls back to the mollifier buffer via `tryMollifiedRunFallback`,
so the page renders correctly. But the per-tick error spam pollutes
Sentry / log aggregation, makes real DB issues hard to spot, and (in
`pnpm dev`) triggers Remix's dev-mode error overlay on every poll.

Switch to `findFirst` + explicit null check that throws a typed
`RunNotInPgError`. The route catches it the same way — the
not-found-in-PG case is now off Prisma's error path entirely. `Run
EnvironmentMismatchError` is unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: d-cs

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

@@ -20,6 +20,20 @@ export class RunEnvironmentMismatchError extends Error {
   }
 }
 
+// Thrown by `call()` when the run isn't in PG. The route loader catches
+// this and falls back to the mollifier buffer via `tryMollifiedRunFallback`.
+// Using a typed error (rather than Prisma's `findFirstOrThrow` exception)
+// keeps the buffered case off the PrismaClient error path — that path
+// emits a `PrismaClient error` log every time it fires, which on the
+// run-detail page polls becomes per-tick log spam and Sentry noise for
+// any run that legitimately lives in the buffer.
+export class RunNotInPgError extends Error {
+  constructor(public readonly runFriendlyId: string) {
+    super(`Run ${runFriendlyId} not in PG`);
+    this.name = "RunNotInPgError";
+  }
+}
+
 export class RunPresenter {
   #prismaClient: PrismaClient;
 
@@ -42,7 +56,13 @@ export class RunPresenter {
     showDeletedLogs: boolean;
     showDebug: boolean;
   }) {
-    const run = await this.#prismaClient.taskRun.findFirstOrThrow({
+    // `findFirst` + explicit null check (not `findFirstOrThrow`) because
+    // a missing PG row is the *expected* path for buffered runs — the
+    // route catches `RunNotInPgError` and falls back to the synthesised
+    // buffer view. `findFirstOrThrow` would log a `PrismaClient error`
+    // every tick of the page poll, masking real DB issues with synthetic
+    // not-found noise.
+    const run = await this.#prismaClient.taskRun.findFirst({
       select: {
         id: true,
         createdAt: true,
@@ -106,6 +126,10 @@ export class RunPresenter {
       },
     });
 
+    if (!run) {
+      throw new RunNotInPgError(runFriendlyId);
+    }
+
     if (environmentSlug !== run.runtimeEnvironment.slug) {
       throw new RunEnvironmentMismatchError(
         `Run ${runFriendlyId} is not in environment ${environmentSlug}`