Enhance internationalization support by integrating language selection for school names, updating UI components for localization, and revising documentation. Implement locale-aware formatting for dates and strings, ensuring a seamless user experience in both Russian and English. Update tests to cover new language features.

src/HSchool.Client/src/style.css

@@ -34,11 +34,39 @@ body {
   right: 16px;
   bottom: 12px;
   display: flex;
+  align-items: center;
   gap: 14px;
   font-size: 12px;
   color: var(--text-muted);
 }
 
+.locale-switch {
+  display: flex;
+  gap: 4px;
+}
+
+.locale-switch__button {
+  padding: 3px 8px;
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  background: transparent;
+  color: var(--text-muted);
+  font: inherit;
+  font-size: 11px;
+  letter-spacing: 0.04em;
+  cursor: pointer;
+}
+
+.locale-switch__button:hover {
+  border-color: var(--accent);
+  color: var(--text);
+}
+
+.locale-switch__button[aria-pressed='true'] {
+  border-color: var(--accent);
+  color: var(--accent);
+}
+
 /* Screens */
 
 .screen__header {