feat: filter receive messages by since

internal/tools/isphere_read.go

@@ -20,6 +20,7 @@ type ReceiveMessagesSource interface {
 type ReceiveMessagesArgs struct {
 	ConversationID string `json:"conversation_id,omitempty" jsonschema:"exact conversation id filter for local readonly message logs"`
 	Query          string `json:"query,omitempty" jsonschema:"case-insensitive keyword filter over message text, subject, ids, and participants"`
+	Since          string `json:"since,omitempty" jsonschema:"RFC3339 timestamp; return messages at or after this time when packet timestamps are available"`
 	Limit          int    `json:"limit,omitempty" jsonschema:"maximum number of messages to return; zero or negative returns all available messages"`
 }
 
@@ -36,6 +37,7 @@ func RegisterISphereReadTools(server *mcp.Server, source ReceiveMessagesSource)
 		result, err := source.ReceiveMessages(ctx, isphere.ReceiveMessagesQuery{
 			ConversationID: input.ConversationID,
 			Query:          input.Query,
+			Since:          input.Since,
 			Limit:          input.Limit,
 		})
 		if err != nil {