fix(notifications): show the mood reminder's real default in the matrix

The /notifications matrix read the constant default table, where the
mood reminder is off, while delivery derives it from the reminder card.
An account receiving the reminder saw every one of its channel switches
off.

The no-row default now lives in one resolver that delivery and the
preferences read both use. GET /api/notifications/preferences publishes
it as `eventDefaults`, the matrix renders a switch without a stored row
from that map, and the reminder card refreshes the matrix when it flips.

docs/api/openapi.yaml

@@ -82724,10 +82724,58 @@ components:
           items:
             type: string
           description: Every event category the server knows, in declaration order — the list a client renders rows for.
+        eventDefaults:
+          type: object
+          propertyNames:
+            type: string
+            enum:
+              - MEDICATION_REMINDER
+              - MEASUREMENT_ANOMALY
+              - COMPLIANCE_LOW
+              - WITHINGS_SYNC_FAILED
+              - SYSTEM_ALERT
+              - PERSONAL_RECORD
+              - MOOD_REMINDER
+              - CYCLE_PERIOD_SOON
+              - CYCLE_PERIOD_CONFIRM
+              - CYCLE_FERTILE_SOON
+              - COACH_NUDGE
+              - MEDICATION_LOW_STOCK
+              - MEASUREMENT_REMINDER
+              - MEDICATION_INTAKE_SYNC
+              - SECURITY_ALERT
+              - DAILY_BRIEFING
+              - SHARED_RECORD_INTAKE
+            description: Notification category a per-channel preference can toggle.
+          additionalProperties:
+            type: boolean
+          required:
+            - MEDICATION_REMINDER
+            - MEASUREMENT_ANOMALY
+            - COMPLIANCE_LOW
+            - WITHINGS_SYNC_FAILED
+            - SYSTEM_ALERT
+            - PERSONAL_RECORD
+            - MOOD_REMINDER
+            - CYCLE_PERIOD_SOON
+            - CYCLE_PERIOD_CONFIRM
+            - CYCLE_FERTILE_SOON
+            - COACH_NUDGE
+            - MEDICATION_LOW_STOCK
+            - MEASUREMENT_REMINDER
+            - MEDICATION_INTAKE_SYNC
+            - SECURITY_ALERT
+            - DAILY_BRIEFING
+            - SHARED_RECORD_INTAKE
+          description: What each event does on a channel with no stored row, resolved for this account by the function delivery
+            uses. Most are constant per category; the mood reminder follows the account's mood-reminder setting
+            (`moodReminderEnabled` on `/api/user/profile`). Render a switch without a row from this map rather than from
+            a copy of the defaults. Since v1.43.11.
       required:
         - channels
         - preferences
         - eventTypes
+        - eventDefaults
       additionalProperties: false
       description: The caller's notification channels, their stored per-event overrides, and the full event vocabulary.
     NotificationChannelSummary:
@@ -82797,9 +82845,8 @@ components:
         - eventType
         - enabled
       additionalProperties: false
-      description: An explicit per-(channel, event) override. Only STORED rows appear — an event with no row here follows the
-        server-side default for that category, which is ON for most and OFF for the opt-in ones (personal records, mood
-        and cycle reminders). Absence is therefore not 'disabled'.
+      description: An explicit per-(channel, event) override. Only STORED rows appear — an event with no row here follows
+        `eventDefaults` on the same response. Absence is therefore not 'disabled'.
     PutNotificationPreferenceResponse:
       type: object
       properties: