Masked email: Fastmail's Masked Email API, MaskedEmail/get and /set (ME-1, ME-7a, ME-16)

Advertised as https://www.fastmail.com/dev/maskedemail in the session and on
every account that may hold masks. Masks created through it start pending
unless the create sets a state; pending can't be set again once left; state
and the other mutable fields map onto the same records the x: API uses.

crates/jmap/src/api/auth.rs

@@ -69,6 +69,8 @@ impl JmapAuthorization for AccessToken {
                 GetRequestMethod::PushSubscription(_) => Permission::JmapPushSubscriptionGet,
                 GetRequestMethod::Sieve(_) => Permission::JmapSieveScriptGet,
                 GetRequestMethod::VacationResponse(_) => Permission::JmapVacationResponseGet,
+                // inbuxa: Fastmail's MaskedEmail (ME-18)
+                GetRequestMethod::MaskedEmail(_) => Permission::SysMaskedEmailGet,
                 GetRequestMethod::Principal(_) => Permission::JmapPrincipalGet,
                 GetRequestMethod::Quota(_) => Permission::JmapQuotaGet,
                 GetRequestMethod::Blob(_) => Permission::JmapBlobGet,
@@ -141,6 +143,14 @@ impl JmapAuthorization for AccessToken {
                         Permission::JmapSieveScriptUpdate,
                         Permission::JmapSieveScriptDestroy,
                     ),
+                    // inbuxa: Fastmail's MaskedEmail (ME-18)
+                    SetRequestMethod::MaskedEmail(s) => validate_set(
+                        s,
+                        self,
+                        Permission::SysMaskedEmailCreate,
+                        Permission::SysMaskedEmailUpdate,
+                        Permission::SysMaskedEmailDestroy,
+                    ),
                     SetRequestMethod::VacationResponse(s) => validate_set(
                         s,
                         self,
@@ -247,7 +257,8 @@ impl JmapAuthorization for AccessToken {
                 | MethodObject::PushSubscription
                 | MethodObject::SearchSnippet
                 | MethodObject::VacationResponse
-                | MethodObject::SieveScript => Permission::JmapEmailChanges,
+                | MethodObject::SieveScript
+                | MethodObject::MaskedEmail => Permission::JmapEmailChanges,
                 // inbuxa: x:MaskedEmail/changes reads what /get reads
                 MethodObject::Registry(object_type) => object_type.get_permission(),
             },