feat: opening a link to a secret ends on its details

As enter on it would, instead of on the vault's list with the secret
selected: ctrl+o, a paste, a clicked link and the share failure
popup's g. Going back to where lazysecrets was left, and Go to, stay
as they were.

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

internal/ui/app/links_test.go

@@ -40,7 +40,8 @@ func TestOpenSecretLink(t *testing.T) {
 	if src, c, s := d.selected(); src != "platform-prod" || c != "kv-app-prod" || s != "api-key" {
 		t.Fatalf("opened %s/%s/%s", src, c, s)
 	}
-	if d.m.focus != paneSecrets || d.m.detail.State() != panes.ValueHidden {
+	// Opened: on its details, as enter on it would; its value hidden.
+	if d.m.focus != paneDetail || d.m.detail.State() != panes.ValueHidden {
 		t.Errorf("focus %d, value state %d", d.m.focus, d.m.detail.State())
 	}
 }