Implement tasks 40, 41, 42: web push, notification bus, reminders engine

Task 40 — Web Push (VAPID):
- Add web-push package + @types/web-push
- pnpm vapid:generate script prints VAPID_PUBLIC_KEY, VAPID_PRIVATE_KEY, NEXT_PUBLIC_VAPID_PUBLIC_KEY
- push_subscriptions schema + migration 0013
- _core/push.ts: sendPush() iterates subscriptions, prunes 404/410 stale entries
- SW push/notificationclick event handlers added to generated sw.js template
- PushOptIn client component on /settings (opt-in, disable, send test)

Task 42 — Notification bus + ntfy adapter:
- notifications table + notif_push/notif_inapp/notif_ntfy user columns (migration 0013)
- _core/notify.ts: notify() fans out to push, in-app DB, and optional ntfy POST
- NotificationBell server component in AppNav: unread badge, dropdown inbox, mark-read
- NotifyChannelToggles client component in /settings

Task 41 — Reminders engine:
- fired_at + created_by added to reminders; default channel changed to 'auto'
- _core/reminders.ts: scheduleReminder (upsert), cancelReminder, listReminders, tickReminders
- tickReminders uses pg_try_advisory_xact_lock for horizontal-scale safety
- src/instrumentation.ts starts reminder worker (30s tick) on Node.js boot
- Notes actions use scheduleReminder/cancelReminder instead of raw SQL
- Calendar createEvent: optional remindMinutesBefore, deleteEvent: cancelReminder
- Calendar-shell: "Remind me 30 min before" checkbox on new event form

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/modules/_core/schema.ts

@@ -26,6 +26,9 @@ export const users = pgTable("users", {
   theme: text("theme").notNull().default("default"),
   themeMode: text("theme_mode").notNull().default("system"),
   completionVisibilityHours: integer("completion_visibility_hours").notNull().default(24),
+  notifPush: boolean("notif_push").notNull().default(true),
+  notifInApp: boolean("notif_inapp").notNull().default(true),
+  notifNtfy: boolean("notif_ntfy").notNull().default(false),
   createdAt: timestamp("created_at", { withTimezone: true }).notNull().defaultNow(),
 });
 
@@ -158,7 +161,9 @@ export const reminders = pgTable(
     entityType: text("entity_type").notNull(),
     entityId: uuid("entity_id").notNull(),
     fireAt: timestamp("fire_at", { withTimezone: true }).notNull(),
-    channel: text("channel").notNull().default("in_app"),
+    channel: text("channel").notNull().default("auto"),
+    firedAt: timestamp("fired_at", { withTimezone: true }),
+    createdBy: uuid("created_by").references(() => users.id, { onDelete: "set null" }),
     createdAt: timestamp("created_at", { withTimezone: true }).notNull().defaultNow(),
   },
   (t) => [
@@ -166,3 +171,35 @@ export const reminders = pgTable(
     index("reminders_household_fire_at_idx").on(t.householdId, t.fireAt),
   ],
 );
+
+export const pushSubscriptions = pgTable(
+  "push_subscriptions",
+  {
+    id: uuid("id").primaryKey().defaultRandom(),
+    userId: uuid("user_id")
+      .notNull()
+      .references(() => users.id, { onDelete: "cascade" }),
+    endpoint: text("endpoint").notNull().unique(),
+    p256dh: text("p256dh").notNull(),
+    auth: text("auth").notNull(),
+    userAgent: text("user_agent"),
+    createdAt: timestamp("created_at", { withTimezone: true }).notNull().defaultNow(),
+  },
+  (t) => [index("push_subscriptions_user_idx").on(t.userId)],
+);
+
+export const notifications = pgTable(
+  "notifications",
+  {
+    id: uuid("id").primaryKey().defaultRandom(),
+    userId: uuid("user_id")
+      .notNull()
+      .references(() => users.id, { onDelete: "cascade" }),
+    title: text("title").notNull(),
+    body: text("body").notNull(),
+    url: text("url"),
+    readAt: timestamp("read_at", { withTimezone: true }),
+    createdAt: timestamp("created_at", { withTimezone: true }).notNull().defaultNow(),
+  },
+  (t) => [index("notifications_user_read_idx").on(t.userId, t.readAt)],
+);