feat(comment): comment on issues and pull requests the gh way

tea issue comment 12 --body "LGTM" failed with "unknown flag: --body"; the
comment had to be created with issue comment create. issue comment and
pr comment now take the issue or pull request and -b/-F/-e directly,
plus --edit-last and --delete-last for your last comment. The
subcommands stay, create is also add, and a misspelled subcommand
suggests the right one.

Comments are written in the configured editor or a multi-line
"Comment (markdown):" field, which edits start from the current text,
without a confirmation afterwards. The new comment's URL goes to stdout
with a ✓ line; deletes ask "Delete comment 81 on alice/x#1?". comment
list shows each comment under a "#79 alice • about 2 hours ago"
heading on a terminal and as key/value blocks when piped, and comment
JSON gains issue_number.

Signed-off-by: bircni <bircni@icloud.com>

internal/services/comments.go

@@ -5,6 +5,8 @@ package services
 
 import (
 	"context"
+	"path"
+	"strconv"
 
 	gitea "gitea.dev/sdk"
 	"gitea.dev/tea/internal/transport"
@@ -18,6 +20,8 @@ type Comment struct {
 	Author    string `json:"author"`
 	CreatedAt string `json:"created_at"`
 	UpdatedAt string `json:"updated_at"`
+	// IssueNumber is the issue or pull request the comment is on.
+	IssueNumber int64 `json:"issue_number"`
 	// Pull reports a comment on a pull request rather than an issue.
 	Pull bool `json:"-"`
 }
@@ -26,9 +30,19 @@ func commentFrom(comment *gitea.Comment) Comment {
 	return Comment{
 		ID: comment.ID, Body: comment.Body, URL: comment.HTMLURL, Author: login(comment.Poster),
 		CreatedAt: timestamp(comment.Created), UpdatedAt: timestamp(comment.Updated), Pull: comment.PRURL != "",
+		IssueNumber: discussionNumber(comment.IssueURL + comment.PRURL),
 	}
 }
 
+// discussionNumber reads the number from the web URL of an issue or pull request, or returns 0.
+func discussionNumber(url string) int64 {
+	n, err := strconv.ParseInt(path.Base(url), 10, 64)
+	if err != nil {
+		return 0
+	}
+	return n
+}
+
 // Comments implements discussion comments under their owning repository resource.
 type Comments struct {
 	Client     *transport.Client