feat: the changelog in the status pane, built in

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

internal/ui/app/app.go

@@ -75,6 +75,8 @@ type Options struct {
 	// and keeps its state, for the status pane.
 	ConfigFiles []string
 	StatePath   string
+	// Changelog is CHANGELOG.md, for the status pane.
+	Changelog string
 	// CacheFile keeps what was loaded between runs; "" keeps it for this
 	// run only.
 	CacheFile string
@@ -185,6 +187,7 @@ type Model struct {
 	configFiles []string
 	statePath   string
 	statusW     int // the status pane's width: the left column's, zoomed or not
+	changelog   []panes.Field
 	cacheDirty  bool
 	sourcesAt   map[string]time.Time
 	placeDir    string
@@ -448,7 +451,7 @@ func New(providers []provider.Provider, opts Options) Model {
 	m.spinning = true
 
 	m.cachePath, m.placeDir, m.sourcesAt = opts.CacheFile, opts.Dir, map[string]time.Time{}
-	m.configFiles, m.statePath = opts.ConfigFiles, opts.StatePath
+	m.configFiles, m.statePath, m.changelog = opts.ConfigFiles, opts.StatePath, changelogFields(opts.Changelog)
 	if m.cachePath != "" {
 		m.loadCacheFile()
 		if len(m.sourceResults) > 0 {