chore(spec): regenerate api-surface and export-origins for the new migration id

`check:generated` proved exactly 2 of 15 artifacts stale (api-surface/,
export-origins/); regenerated exactly those two with the package's own
generators. Each diff is one line naming NOTIFICATION_EVENT_MIGRATION_ID and its
declaration file — nothing else moved.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ARYe3yQTQCUFm5qPYNgKaJ

Author: claude

packages/spec/api-surface/system.json

@@ -444,6 +444,7 @@
     "MutualTLSConfig (type)",
     "MutualTLSConfigParsed (type)",
     "MutualTLSConfigSchema (const)",
+    "NOTIFICATION_EVENT_MIGRATION_ID (const)",
     "NavNodeLike (interface)",
     "NotificationChannel (type)",
     "NotificationChannelSchema (const)",

packages/spec/export-origins/system.json

@@ -444,6 +444,7 @@
     "MutualTLSConfig": "src/system/auth-config.zod.ts#MutualTLSConfig (type)",
     "MutualTLSConfigParsed": "src/system/auth-config.zod.ts#MutualTLSConfigParsed (type)",
     "MutualTLSConfigSchema": "src/system/auth-config.zod.ts#MutualTLSConfigSchema (const)",
+    "NOTIFICATION_EVENT_MIGRATION_ID": "src/system/migration.zod.ts#NOTIFICATION_EVENT_MIGRATION_ID (const)",
     "NavNodeLike": "src/system/i18n-resolver.ts#NavNodeLike (interface)",
     "NotificationChannel": "src/system/notification.zod.ts#NotificationChannel (type)",
     "NotificationChannelSchema": "src/system/notification.zod.ts#NotificationChannelSchema (const)",