feat: initial release with 48 Mattermost MCP tools

- 27 base tools: channels, messaging, users, reactions, files, DMs
- Team management: invite/remove users, get stats, list members
- Slash commands: execute /remind, /poll, etc.
- Webhook management: incoming and outgoing webhooks
- System tools: server config, logs, bulk status updates
- Channel admin: create, invite, leave, delete channels
- Read-only mode for safe exploration
- Dual token support (bot + PAT) for enhanced security
- Apache 2.0 licensed

operation/reaction/slim.go

@@ -0,0 +1,15 @@
+package reaction
+
+import "github.com/mattermost/mattermost-server/v6/model"
+
+func SlimReaction(r *model.Reaction) map[string]interface{} {
+	if r == nil {
+		return nil
+	}
+	return map[string]interface{}{
+		"user_id":    r.UserId,
+		"post_id":    r.PostId,
+		"emoji_name": r.EmojiName,
+		"create_at":  r.CreateAt,
+	}
+}