chore(spec): record features.emailDelivery in the authorable-surface snapshot

Claude-Session: https://claude.ai/code/session_01Utp6CbSX6BdpVNjS79LB5A
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

packages/spec/authorable-surface/api.json

@@ -214,6 +214,7 @@
     "api/AuthFeaturesConfig:cloudManaged",
     "api/AuthFeaturesConfig:degradedTenancy",
     "api/AuthFeaturesConfig:deviceAuthorization",
+    "api/AuthFeaturesConfig:emailDelivery",
     "api/AuthFeaturesConfig:magicLink [RETIRED]",
     "api/AuthFeaturesConfig:multiOrgEnabled",
     "api/AuthFeaturesConfig:oidcProvider",