Refactor terminology in dialogs and tables for consistency; update styles for number inputs and footer links

src/Duempelkas.Desktop/wwwroot/css/app.css

@@ -170,6 +170,18 @@ html, body {
     text-align: center;
 }
 
+.app-footer-about {
+    color: var(--color-text-muted);
+    text-decoration: underline;
+    padding: 0;
+}
+
+.app-footer-about:hover,
+.app-footer-about:focus {
+    color: var(--color-text);
+    cursor: pointer;
+}
+
 /* Buttons – modern style */
 .btn {
     font-size: 0.85rem;
@@ -525,6 +537,17 @@ html, body {
     text-align: right;
 }
 
+.no-spinner::-webkit-outer-spin-button,
+.no-spinner::-webkit-inner-spin-button {
+    -webkit-appearance: none;
+    margin: 0;
+}
+
+input[type="number"].no-spinner {
+    -moz-appearance: textfield;
+    appearance: textfield;
+}
+
 .form-control, .form-select {
     border-radius: 0.5rem;
     transition: border-color 0.15s, box-shadow 0.15s;