added new requirements and fix UI bugs

src/modules/client/components/LessonBlock.jsx

@@ -24,7 +24,7 @@ function LessonSkeleton() {
  *                 when the caller already renders its own lesson header
  *                 above (e.g. LessonDetails), to avoid showing it twice.
  */
-const LessonBlock = ({ lesson, loading = false, showHeader = true }) => {
+const LessonBlock = ({ lesson, loading = false, showHeader = true, onWatchProgress }) => {
   if (!lesson && !loading) {
     return (
       <div className="h-full w-full flex items-center justify-center text-muted-foreground py-20">
@@ -45,6 +45,7 @@ const LessonBlock = ({ lesson, loading = false, showHeader = true }) => {
           blocks={lesson.blocks ?? []}
           empty="No content blocks yet."
           showHeader={showHeader}
+          onWatchProgress={onWatchProgress}
         />
       </div>
     </PreviewChrome>

src/modules/client/components/MarkCompleteButton.jsx

@@ -0,0 +1,35 @@
+import { useState } from "react";
+import { CheckCircle2 } from "lucide-react";
+import { Button } from "@/components/ui/button";
+
+/**
+ * Explicit self-report completion button, backing the manual_complete
+ * completion requirement type. Renders as already-completed (disabled,
+ * checkmark) once the lesson is marked done.
+ */
+export default function MarkCompleteButton({ label, completed, onMarkComplete }) {
+  const [saving, setSaving] = useState(false);
+
+  const handleClick = async () => {
+    if (completed || saving) return;
+    setSaving(true);
+    await onMarkComplete?.();
+    setSaving(false);
+  };
+
+  return (
+    <div className="flex justify-center py-6">
+      <Button
+        type="button"
+        size="lg"
+        variant={completed ? "outline" : "default"}
+        disabled={completed || saving}
+        onClick={handleClick}
+        className="gap-2"
+      >
+        <CheckCircle2 className="size-4" />
+        {completed ? "Completed" : saving ? "Marking complete…" : (label || "Mark Complete")}
+      </Button>
+    </div>
+  );
+}