refactor: no expiring command, and a file's last commit is its hash and age

The status pane already lists what's expiring. The last commit no longer
names who made it or its message.

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

internal/provider/repo/repo_test.go

@@ -505,7 +505,7 @@ func TestFileDetails(t *testing.T) {
 
 	d := details("secrets/app.yaml")
 	if d["encryption"].Value != "sops · age" || d["keys"].Value != "age age1xxxx" || d["git"].Value != "tracked" ||
-		!strings.Contains(d["last commit"].Value, "t: files") || d["encrypted"].Value == "" {
+		!strings.HasSuffix(d["last commit"].Value, " ago") || strings.Contains(d["last commit"].Value, ":") || d["encrypted"].Value == "" {
 		t.Errorf("sops yaml: %+v", d)
 	}
 	if d := details("prod.env"); d["keys"].Value != "age age1xxxx" {