(new): support Bot API 10.3

(fix): finalize v2 contracts
(tests): cover v2 migration
(doc): prepare release guidance

tgapi/chat_types.go

@@ -90,8 +90,7 @@ type ChatFullInfo struct {
 
 	// AvailableReaction Optional. List of available reactions allowed in the chat. If omitted, then all emoji
 	// reactions are allowed.
-	// Subject to change in v2: the Go field name may be pluralized to AvailableReactions.
-	AvailableReaction []ReactionType `json:"available_reactions,omitempty"`
+	AvailableReactions []ReactionType `json:"available_reactions,omitempty"`
 
 	// BackgroundCustomEmojiID Optional. Custom emoji identifier of the emoji chosen by the chat for the reply
 	// header and link preview background
@@ -358,6 +357,8 @@ type ChatMember struct {
 	CanEditStories *bool `json:"can_edit_stories,omitempty"` // Since: Bot API 6.9
 	// CanDeleteStories True, if the administrator can delete stories posted by other users
 	CanDeleteStories *bool `json:"can_delete_stories,omitempty"` // Since: Bot API 6.9
+	// CanSendWelcomeMessages reports whether the administrator can manage chat welcome messages or send them as a bot.
+	CanSendWelcomeMessages *bool `json:"can_send_welcome_messages,omitempty"` // Since: Bot API 10.3
 
 	// CanPostMessages Optional. True, if the administrator can post messages in the channel, approve suggested
 	// posts, or access channel statistics; for channels only
@@ -534,6 +535,8 @@ type ChatAdministratorRights struct {
 	// CanManageTags Optional. True, if the administrator can edit the tags of regular members; for groups and
 	// supergroups only. If omitted, defaults to the value of can_pin_messages.
 	CanManageTags *bool `json:"can_manage_tags,omitempty"`
+	// CanSendWelcomeMessages reports whether the administrator can manage chat welcome messages or send them as a bot.
+	CanSendWelcomeMessages *bool `json:"can_send_welcome_messages,omitempty"` // Since: Bot API 10.3
 }
 
 // ChatBoostUpdated represents a boost added to a chat or changed.
@@ -578,6 +581,14 @@ type CommunityChatAdded struct {
 	Community Community `json:"community"`
 }
 
+// CommunityChatJoined describes a service message about a chat being joined by a user from a community.
+//
+// Since: Bot API 10.3
+type CommunityChatJoined struct {
+	// Community contains information about the community from which the user joined the chat.
+	Community Community `json:"community"`
+}
+
 // CommunityChatRemoved describes a service message about a chat leaving a community.
 //
 // Since: Bot API 10.2