feat(run-engine): typed ExecutionSnapshotNotFoundError from getExecutionSnapshotsSince

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

Author: d-cs

internal-packages/run-engine/src/engine/errors.ts

@@ -104,3 +104,10 @@ export class RunOneTimeUseTokenError extends Error {
     this.name = "RunOneTimeUseTokenError";
   }
 }
+
+export class ExecutionSnapshotNotFoundError extends Error {
+  constructor(public readonly snapshotId: string) {
+    super(`No execution snapshot found for id ${snapshotId}`);
+    this.name = "ExecutionSnapshotNotFoundError";
+  }
+}

internal-packages/run-engine/src/engine/systems/executionSnapshotSystem.ts

@@ -10,6 +10,7 @@ import {
   TaskRunStatus,
   Waitpoint,
 } from "@trigger.dev/database";
+import { ExecutionSnapshotNotFoundError } from "../errors.js";
 import { HeartbeatTimeouts } from "../types.js";
 import { SystemResources } from "./systems.js";
 
@@ -278,7 +279,7 @@ export async function getExecutionSnapshotsSince(
   });
 
   if (!sinceSnapshot) {
-    throw new Error(`No execution snapshot found for id ${sinceSnapshotId}`);
+    throw new ExecutionSnapshotNotFoundError(sinceSnapshotId);
   }
 
   // Step 2: Fetch snapshots WITHOUT waitpoints to avoid N×M data explosion