feat: link each changelog entry to its PR and commit

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

internal/update/update.go

@@ -22,6 +22,7 @@ import (
 	"os/exec"
 	"path"
 	"path/filepath"
+	"regexp"
 	"runtime"
 	"strings"
 	"time"
@@ -49,9 +50,13 @@ type Release struct {
 // every release ends with.
 func (r Release) Notes() string {
 	notes, _, _ := strings.Cut(r.Body, "## Install")
-	return strings.TrimSpace(notes)
+	return mdLink.ReplaceAllString(strings.TrimSpace(notes), "$1")
 }
 
+// mdLink is a Markdown link, [text](url): the notes link PRs and commits,
+// and a terminal shows them as their text.
+var mdLink = regexp.MustCompile(`\[([^\]]+)\]\((https?://[^)\s]+)\)`)
+
 // Client talks to the release server.
 type Client struct {
 	API  string // the repository's API, DefaultAPI when empty