fix(website): connect box-art in plaintext output blocks

Tighten line-height (1.75 -> 1.2) on plaintext code blocks only, so the
box-drawing in rendered output (tables, query results, plan trees)
connects vertically as it does in the app. Command blocks keep the
looser spacing.

website/src/styles/global.css

@@ -15,6 +15,18 @@
 	-webkit-user-select: none;
 }
 
+/* Rendered terminal-output blocks (box-drawn tables, query output, plan trees)
+   are fenced as plain ``` → `plaintext`. They contain box-drawing art whose
+   vertical lines only connect at terminal-style line spacing; Starlight's
+   default code line-height (1.75) leaves visible gaps between the rows.
+   Tighten just these blocks so the art renders connected, as it does in the
+   app. Command blocks (`rdbms` / `sql` / `sh`) keep the looser spacing.
+   The value is a balance of connected box-art vs. readability — nudge toward
+   1.0 if any hairline gaps remain on your display. */
+pre[data-language='plaintext'] .ec-line {
+	line-height: 1.2;
+}
+
 /* The app's input field is single-line, so a multi-command copy can't be
    pasted-and-run as one unit. Hide Expressive Code's copy button on
    *multi-line* `rdbms` blocks (each line is a separate command — type them