fix(terminal): Keep the cursor to the font height instead of the whole line

With a line height above 1, xterm's DOM renderer stretched the cursor cell
over the full row. Size it to the font's own height and centre it with the glyphs.

src/features/terminal/Terminal.module.css

@@ -67,6 +67,16 @@
 .pane :global(.xterm) {
   height: 100%;
 }
+/* xterm's DOM renderer stretches the cursor cell over the whole row (line height
+   included); keep it to the font's own height, centred like the glyphs. */
+.pane :global(.xterm-rows .xterm-cursor) {
+  position: relative;
+  top: 50%;
+  height: auto;
+  max-height: 100%;
+  line-height: normal;
+  transform: translateY(-50%);
+}
 .pane :global(.xterm-viewport) {
   background-color: var(--bg-island, var(--bg-app)) !important;
 }