fix: 'Pause sending by' is off by default everywhere

The optional 'Pause sending by' deadline was defaulting to 18 (= 6 PM)
in three places:
  - reminders.delivery_window_end_hour schema default (NOT NULL DEFAULT 18)
  - createReminderAction / editScheduleAction fallback when the field
    is missing on the input
  - the Zod refine validator's secondary fallback

Net effect: any reminder created before this change has 18 in the DB,
so the edit form's checkbox flips ON automatically (the wizard treats
'value !== undefined && value !== 24' as 'opted in'). The wizard's
own create flow always sends 24 explicitly when the box is unchecked
— but legacy / direct API payloads + the schema default for older rows
don't carry that intent through.

Switch every default to 24 (the off-sentinel the wizard already uses)
so the optional toggle stays off until the operator ticks it. New
migration 0012 also backfills existing rows from 18 → 24 so editing
old reminders no longer auto-checks 'Pause sending by'.

Tests in when-form-deadline.test.tsx already lock in the UI contract
(off when initialDeliveryEndHour is undefined or 24, on for any other
value). No assertion changes needed.

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

apps/web/src/actions/reminders.ts

@@ -271,7 +271,7 @@ const createReminderSchema = z
       path: ["messages"],
     },
   )
-  .refine((d) => (d.deliveryWindowStartHour ?? 6) < (d.deliveryWindowEndHour ?? 18), {
+  .refine((d) => (d.deliveryWindowStartHour ?? 6) < (d.deliveryWindowEndHour ?? 24), {
     message: "Delivery window start must be earlier than end",
     path: ["deliveryWindowStartHour"],
   });
@@ -328,7 +328,11 @@ export async function createReminderAction(
     timezone,
   } = parsed.data;
   const deliveryWindowStartHour = parsed.data.deliveryWindowStartHour ?? 6;
-  const deliveryWindowEndHour = parsed.data.deliveryWindowEndHour ?? 18;
+  // 24 = "no deadline" (off). The wizard sends 24 explicitly when the
+  // operator hasn't ticked the optional "Pause sending by" checkbox;
+  // fall back to 24 here so legacy payloads / direct API calls don't
+  // accidentally enable the deadline at 6pm.
+  const deliveryWindowEndHour = parsed.data.deliveryWindowEndHour ?? 24;
   const parts = resolveMessageParts(parsed.data);
 
   const op = await getSeededOperator();
@@ -442,7 +446,11 @@ export async function updateReminderAction(
     timezone,
   } = parsed.data;
   const deliveryWindowStartHour = parsed.data.deliveryWindowStartHour ?? 6;
-  const deliveryWindowEndHour = parsed.data.deliveryWindowEndHour ?? 18;
+  // 24 = "no deadline" (off). The wizard sends 24 explicitly when the
+  // operator hasn't ticked the optional "Pause sending by" checkbox;
+  // fall back to 24 here so legacy payloads / direct API calls don't
+  // accidentally enable the deadline at 6pm.
+  const deliveryWindowEndHour = parsed.data.deliveryWindowEndHour ?? 24;
   const parts = resolveMessageParts(parsed.data);
 
   const op = await getSeededOperator();

packages/db/migrations/0012_lucky_masked_marvel.sql

@@ -0,0 +1,10 @@
+-- Switch the default to 24 ("no deadline" sentinel) so newly-created
+-- reminders are off-by-default for the optional "Pause sending by"
+-- toggle, matching the wizard's UX contract.
+ALTER TABLE "reminders" ALTER COLUMN "delivery_window_end_hour" SET DEFAULT 24;
+-- Existing rows still hold the old default (18). Treat those as
+-- "schema-default, never opted in by the operator" and clear them to
+-- 24 so editing an old reminder doesn't auto-check the deadline box.
+-- Operators who actually wanted a 6pm deadline can re-enable it from
+-- the edit form.
+UPDATE "reminders" SET "delivery_window_end_hour" = 24 WHERE "delivery_window_end_hour" = 18;

packages/db/migrations/meta/_journal.json

@@ -85,6 +85,13 @@
       "when": 1778464002000,
       "tag": "0011_premium_grandmaster",
       "breakpoints": true
+    },
+    {
+      "idx": 12,
+      "version": "7",
+      "when": 1778412502601,
+      "tag": "0012_lucky_masked_marvel",
+      "breakpoints": true
     }
   ]
 }

packages/db/src/schema.ts

@@ -92,8 +92,11 @@ export const reminders = pgTable("reminders", {
   // Delivery window (operator timezone). End hour is enforced at runtime
   // by fire-reminder when window enforcement lands; start hour is documented
   // here but not gated in v1.
+  // 24 is the "no deadline" sentinel — it's the off-by-default state so a
+  // reminder created without the operator explicitly opting into "Pause
+  // sending by" stays unbounded.
   deliveryWindowStartHour: integer("delivery_window_start_hour").notNull().default(6),
-  deliveryWindowEndHour: integer("delivery_window_end_hour").notNull().default(18),
+  deliveryWindowEndHour: integer("delivery_window_end_hour").notNull().default(24),
 });
 
 export const reminderTargets = pgTable(