fix(FN-0000): stabilize automation cron scheduling and SSE coverage

packages/core/src/automation-store.test.ts

@@ -81,6 +81,12 @@ describe("AutomationStore", () => {
       expect(new Date(next).getUTCHours()).toBe(13);
       expect(new Date(next).getUTCMinutes()).toBe(0);
     });
+
+    it("computes monthly runs against UTC instead of local machine time", () => {
+      const fromDate = new Date("2026-04-15T00:00:00Z");
+      const next = store.computeNextRun("0 0 1 * *", fromDate);
+      expect(next).toBe("2026-05-01T00:00:00.000Z");
+    });
   });
 
   // ── createSchedule ────────────────────────────────────────────────

packages/core/src/automation-store.ts

@@ -12,6 +12,8 @@ import { AUTOMATION_PRESETS, MAX_RUN_HISTORY } from "./automation.js";
 import type { ScheduleType } from "./automation.js";
 import { Database, fromJson } from "./db.js";
 
+const CRON_TIMEZONE = "UTC";
+
 export interface AutomationStoreEvents {
   "schedule:created": [schedule: ScheduledTask];
   "schedule:updated": [schedule: ScheduledTask];
@@ -170,6 +172,7 @@ export class AutomationStore extends EventEmitter<AutomationStoreEvents> {
   computeNextRun(cronExpression: string, fromDate?: Date): string {
     const interval = CronExpressionParser.parse(cronExpression, {
       currentDate: fromDate ?? new Date(),
+      tz: CRON_TIMEZONE,
     });
     const next = interval.next();
     return next.toISOString() ?? new Date(next.getTime()).toISOString();

packages/core/src/automation.test.ts

@@ -41,6 +41,7 @@ const allScheduleTypesRecord: Record<ScheduleType, true> = {
 };
 
 const allScheduleTypes = Object.keys(allScheduleTypesRecord) as ScheduleType[];
+const CRON_TIMEZONE = "UTC";
 
 function cronDateToDate(value: { toISOString(): string | null; getTime(): number }): Date {
   const iso = value.toISOString();
@@ -50,6 +51,7 @@ function cronDateToDate(value: { toISOString(): string | null; getTime(): number
 function parseNextRun(cronExpression: string, currentDate?: Date): Date {
   const interval = CronExpressionParser.parse(cronExpression, {
     currentDate: currentDate ?? new Date(),
+    tz: CRON_TIMEZONE,
   });
   return cronDateToDate(interval.next());
 }
@@ -287,6 +289,7 @@ describe("Preset cron expression edge cases", () => {
   it("ensures weekdays preset never schedules Saturday or Sunday in the next 7 runs", () => {
     const interval = CronExpressionParser.parse(AUTOMATION_PRESETS.weekdays, {
       currentDate: new Date("2026-04-06T00:00:00.000Z"), // Monday
+      tz: CRON_TIMEZONE,
     });
 
     const days = Array.from({ length: 7 }, () => cronDateToDate(interval.next()).getUTCDay());
@@ -301,6 +304,7 @@ describe("Preset cron expression edge cases", () => {
   it("ensures every15Minutes preset advances in 15 minute intervals", () => {
     const interval = CronExpressionParser.parse(AUTOMATION_PRESETS.every15Minutes, {
       currentDate: new Date("2026-01-01T00:00:00.000Z"),
+      tz: CRON_TIMEZONE,
     });
 
     const first = cronDateToDate(interval.next());
@@ -314,6 +318,7 @@ describe("Preset cron expression edge cases", () => {
   it("ensures every2Hours preset advances in 2 hour intervals", () => {
     const interval = CronExpressionParser.parse(AUTOMATION_PRESETS.every2Hours, {
       currentDate: new Date("2026-01-01T00:00:00.000Z"),
+      tz: CRON_TIMEZONE,
     });
 
     const first = cronDateToDate(interval.next());

packages/core/src/routine-store.test.ts

@@ -71,6 +71,12 @@ describe("RoutineStore", () => {
       expect(new Date(next).getUTCHours()).toBe(13);
       expect(new Date(next).getUTCMinutes()).toBe(0);
     });
+
+    it("computes monthly runs against UTC instead of local machine time", () => {
+      const fromDate = new Date("2026-04-15T00:00:00Z");
+      const next = store.computeNextRun("0 0 1 * *", fromDate);
+      expect(next).toBe("2026-05-01T00:00:00.000Z");
+    });
   });
 
   // ── createRoutine ────────────────────────────────────────────────

packages/core/src/routine-store.ts

@@ -26,6 +26,8 @@ import {
   MAX_ROUTINE_RUN_HISTORY,
 } from "./routine.js";
 
+const CRON_TIMEZONE = "UTC";
+
 export interface RoutineStoreEvents {
   "routine:created": [routine: Routine];
   "routine:updated": [routine: Routine];
@@ -242,6 +244,7 @@ export class RoutineStore extends EventEmitter<RoutineStoreEvents> {
   computeNextRun(cronExpression: string, fromDate?: Date): string {
     const interval = CronExpressionParser.parse(cronExpression, {
       currentDate: fromDate ?? new Date(),
+      tz: CRON_TIMEZONE,
     });
     const next = interval.next();
     return new Date(next.getTime()).toISOString();