feat(ql3): establish 3.0 incubation baseline

back/runtime/ports/primaryTimeoutSource.ts

@@ -0,0 +1,26 @@
+export const MAX_PRIMARY_TIMEOUT_BATCH_SIZE = 64;
+
+export interface PrimaryTimeoutCursor {
+  deadlineAtMs: number;
+  attemptId: string;
+}
+
+export interface PrimaryTimeoutCandidate {
+  runId: string;
+  attemptId: string;
+  deadlineAtMs: number;
+}
+
+export interface PrimaryTimeoutPage {
+  candidates: readonly PrimaryTimeoutCandidate[];
+  truncated: boolean;
+  nextCursor?: PrimaryTimeoutCursor;
+}
+
+export interface PrimaryTimeoutSource {
+  listOverdue(options: {
+    nowMs: number;
+    cursor?: PrimaryTimeoutCursor;
+    limit?: number;
+  }): Promise<PrimaryTimeoutPage>;
+}