chore: migrate messaging REST API to Opt[T]

Follow-up to the rebase onto master's repo-wide Option[T] -> Opt[T] change
(#4035). Converts the code this branch adds to the new convention:

- messaging/rest_api/types.nim: MessagingJsonEnvelope fields to Opt[T],
  Opt.some/Opt.none, and json_serialization/pkg/results instead of
  json_serialization/std/options.
- tests: WakuNodeConf.clusterId is now Opt[uint16]; DTO fields are Opt.

`Option[ContentBody]` in the handlers is presto's own API and stays as-is.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

logos_delivery/messaging/rest_api/types.nim

@@ -5,7 +5,7 @@ import
   chronicles,
   results,
   json_serialization,
-  json_serialization/std/options,
+  json_serialization/pkg/results,
   presto/[route, client, common]
 import
   logos_delivery/waku/common/base64,
@@ -22,8 +22,8 @@ type MessagingJsonEnvelope* = object
   ## `payload` / `meta` are base64. Fields mirror `MessageEnvelope` exactly.
   payload*: Base64String
   contentTopic*: ContentTopic
-  ephemeral*: Option[bool]
-  meta*: Option[Base64String]
+  ephemeral*: Opt[bool]
+  meta*: Opt[Base64String]
 
 type MessagingPostMessageRequest* = MessagingJsonEnvelope
 
@@ -66,10 +66,10 @@ proc readValue*(
     reader: var JsonReader[RestJson], value: var MessagingJsonEnvelope
 ) {.raises: [SerializationError, IOError].} =
   var
-    payload = none(Base64String)
-    contentTopic = none(ContentTopic)
-    ephemeral = none(bool)
-    meta = none(Base64String)
+    payload = Opt.none(Base64String)
+    contentTopic = Opt.none(ContentTopic)
+    ephemeral = Opt.none(bool)
+    meta = Opt.none(Base64String)
 
   var keys = initHashSet[string]()
   for fieldName in readObjectFields(reader):
@@ -84,13 +84,13 @@ proc readValue*(
 
     case fieldName
     of "payload":
-      payload = some(reader.readValue(Base64String))
+      payload = Opt.some(reader.readValue(Base64String))
     of "contentTopic":
-      contentTopic = some(reader.readValue(ContentTopic))
+      contentTopic = Opt.some(reader.readValue(ContentTopic))
     of "ephemeral":
-      ephemeral = some(reader.readValue(bool))
+      ephemeral = Opt.some(reader.readValue(bool))
     of "meta":
-      meta = some(reader.readValue(Base64String))
+      meta = Opt.some(reader.readValue(Base64String))
     else:
       unrecognizedFieldWarning(value)
 
@@ -117,7 +117,7 @@ proc writeValue*(
 proc readValue*(
     reader: var JsonReader[RestJson], value: var MessagingSendResponse
 ) {.raises: [SerializationError, IOError].} =
-  var requestId = none(string)
+  var requestId = Opt.none(string)
 
   var keys = initHashSet[string]()
   for fieldName in readObjectFields(reader):
@@ -131,7 +131,7 @@ proc readValue*(
 
     case fieldName
     of "requestId":
-      requestId = some(reader.readValue(string))
+      requestId = Opt.some(reader.readValue(string))
     else:
       unrecognizedFieldWarning(value)
 
@@ -214,7 +214,7 @@ proc readValue*(
     reader: var JsonReader[RestJson], value: var SendEventRecord
 ) {.raises: [SerializationError, IOError].} =
   var
-    kind = none(SendEventKind)
+    kind = Opt.none(SendEventKind)
     messageHash = ""
     error = ""
     timestamp = int64(0)
@@ -222,7 +222,7 @@ proc readValue*(
   for fieldName in readObjectFields(reader):
     case fieldName
     of "kind":
-      kind = some(reader.readValue(SendEventKind))
+      kind = Opt.some(reader.readValue(SendEventKind))
     of "messageHash":
       messageHash = reader.readValue(string)
     of "error":

tests/api/test_entry_layer.nim

@@ -27,7 +27,7 @@ proc nodeConf(entryLayer: EntryLayer, rest = false): WakuNodeConf =
   conf.listenAddress = parseIpAddress("0.0.0.0")
   conf.tcpPort = Port(0)
   conf.discv5UdpPort = Port(0)
-  conf.clusterId = some(3'u16)
+  conf.clusterId = Opt.some(3'u16)
   conf.numShardsInNetwork = 1
   conf.rest = rest
   conf.restAddress = parseIpAddress("127.0.0.1")

tests/api/test_messaging_rest.nim

@@ -34,7 +34,7 @@ proc restNodeConf(): WakuNodeConf =
   conf.listenAddress = parseIpAddress("0.0.0.0")
   conf.tcpPort = Port(0)
   conf.discv5UdpPort = Port(0)
-  conf.clusterId = some(3'u16)
+  conf.clusterId = Opt.some(3'u16)
   conf.numShardsInNetwork = 1
   conf.rest = true
   conf.restAddress = parseIpAddress("127.0.0.1")
@@ -66,8 +66,8 @@ suite "Messaging REST API":
     let msg = MessagingJsonEnvelope(
       payload: base64.encode("hello rest"),
       contentTopic: contentTopic,
-      ephemeral: none(bool),
-      meta: none(Base64String),
+      ephemeral: Opt.none(bool),
+      meta: Opt.none(Base64String),
     )
     let sendResp = await client.messagingPostMessagesV1(msg)
     check: