fix(schema-diff): keep compare action reachable

apps/desktop/src/components/diff/SchemaDiffDialog.vue

@@ -870,10 +870,16 @@ const targetConnectionInfo = computed(() => {
         </DialogTitle>
       </DialogHeader>
 
-      <div class="flex-1 min-h-0 overflow-hidden flex flex-col">
+      <!-- Result step relies on splitpanes to manage its own scroll/heights, so it keeps
+           `overflow-hidden`; the config step's tall content (e.g. the table multi-select
+           added in the "compare specific tables" feature) can overflow a fixed-height
+           dialog, so it must be allowed to scroll vertically instead of being clipped --
+           otherwise the Compare button at the bottom becomes unreachable. -->
+      <div :class="[step === 'result' ? 'overflow-hidden' : 'overflow-y-auto', 'flex-1 min-h-0 flex flex-col']">
         <!-- Config Step -->
         <SchemaDiffConfigStep
           v-if="step === 'config'"
+          class="shrink-0"
           v-model:source-connection-id="sourceConnectionId"
           v-model:source-database="sourceDatabase"
           v-model:source-schema="sourceSchema"

apps/desktop/src/components/diff/__tests__/SchemaDiffDialog.spec.ts

@@ -26,4 +26,17 @@ describe("SchemaDiffDialog fullscreen layout", () => {
   it("lets the deploy confirm dialog body shrink so a long destructive statement can't push the footer buttons off-screen", () => {
     expect(dialogSource).toContain('<div class="py-2 space-y-3 min-w-0">');
   });
+
+  it("lets the config step scroll vertically so the Compare button stays reachable when 'compare specific tables' is enabled", () => {
+    // Regression for #6627: the "compare specific tables" feature (#6533/#6540) grows the
+    // config step (table multi-select + same-name match). Under a fixed-height dialog that
+    // step used to be clipped (`overflow-hidden`), pushing the Compare button below the
+    // visible area with no way to scroll to it. The container must scroll on all steps
+    // except the result step, which relies on splitpanes to manage its own height.
+    expect(dialogSource).toContain("step === 'result' ? 'overflow-hidden' : 'overflow-y-auto'");
+    // The config step must not be flex-shrunk (which would swallow its height and suppress
+    // the scrollbar); only then does the taller-than-dialog content actually overflow and
+    // become reachable via scrolling.
+    expect(dialogSource).toMatch(/<SchemaDiffConfigStep\n[\s\S]*?class="shrink-0"/);
+  });
 });