v0.319.0: the app page in panels, the login in one place, a password the box never had is said in words

- style A (operator 2026-10-16): hero, tab bar and every section are panels on --bg-1, one width, 16px apart;
  the install page's form groups use the same rule; the settings tab's 700px inner wrapper is gone
- „Belépés az alkalmazásba": name + password side by side, fetched on demand (R-254, R-709); pairing in app_login.go
- the empty-value rule: no stored value -> a sentence, never an eye; page and reveal endpoint share storedValuePresent
- „Cím és kulcsok" is rows (no Domain input, no disabled storage select, no install form); hint under the title
- tests red-proved: app_page_tuning_test.go (4); 36 app-page parity fixtures re-captured, 4 new; install fixtures unchanged

Claude-Session: https://claude.ai/code/session_012qRErfCoiTkvDK9N5XHbzb

controller/internal/web/launcher_polish_test.go

@@ -115,9 +115,11 @@ func TestAppInfo_HeroPlaceholder_ScreenshotsUntouched(t *testing.T) {
 	if !strings.Contains(html, canonical3Step) {
 		t.Error("app_info hero logo must use the canonical 3-step chain")
 	}
-	// Screenshots must be byte-identical to before — they still vanish on error, no placeholder.
-	if !strings.Contains(html, `class="app-screenshot"`) || !strings.Contains(html, `onerror="this.style.display='none'"`) {
-		t.Error("app_info screenshot imgs must keep their original vanish-on-error onerror")
+	// Screenshots still vanish on error, no placeholder. v0.319.0: through appShotGone, which also
+	// hides the screenshots panel when the last one is gone — a panel around nothing is not drawn.
+	if !strings.Contains(html, `class="app-screenshot"`) || !strings.Contains(html, `onerror="appShotGone(this)"`) ||
+		!strings.Contains(html, "img.style.display = 'none';") {
+		t.Error("app_info screenshot imgs must vanish on error")
 	}
 	if strings.Contains(html, `class="app-screenshot" `) && strings.Contains(html, `app-screenshot" data-fallback`) {
 		t.Error("app_info screenshots must NOT gain a placeholder fallback")