fix: add Shiki SQL syntax highlighting to all SQL display components

Add useSqlHighlighter composable and integrate Shiki highlighting into
DangerConfirmDialog, QueryHistory, DataGrid (replacing regex-based
highlighting), SqlFileExecutionDialog, SchemaDiffDialog, TreeItem,
ObjectBrowser, and FieldLineageDialog. Also fix danger dialog overflow
by adding overflow-hidden to DialogContent and wrap/scroll support.

apps/desktop/src/composables/useSqlHighlighter.ts

@@ -0,0 +1,20 @@
+import { computed, onMounted, ref } from "vue";
+import { useTheme } from "@/composables/useTheme";
+import { type SqlHighlighter, createShikiSqlHighlighter } from "@/lib/sqlHighlighter";
+
+export function useSqlHighlighter() {
+  const { isDark } = useTheme();
+  const sqlHighlighter = ref<SqlHighlighter>();
+
+  onMounted(async () => {
+    sqlHighlighter.value = await createShikiSqlHighlighter({
+      appearance: () => (isDark.value ? "dark" : "light"),
+    });
+  });
+
+  function highlight(sql: string): string {
+    return sqlHighlighter.value?.(sql) ?? sql;
+  }
+
+  return { highlight, sqlHighlighter };
+}