fix(course): restore mobile mark complete and outline progress card (#942)

* fix(course): pass progress into mobile outline sheet card

The outline sheet bound CourseProgressCard with {courseProgress}, which
sets a courseProgress prop the card does not read. progress was
undefined, so opening the sheet crashed on progress.percent. Pass
progress={courseProgress} and treat missing progress as zeros.

Co-authored-by: Rotimi Best <rotimi-best@users.noreply.github.com>

* fix(course): keep mark complete on mobile student lessons

The mobile bottom nav hid the whole lesson action row, so students had no way to mark a lesson complete. Hide only prev/next when the bottom bar is shown.

Co-authored-by: Rotimi Best <rotimi-best@users.noreply.github.com>

* fix(course): show a check on the right of a completed lesson title

When a student marks a lesson complete, hide the disabled Mark as Complete
button and place a filled check icon on the right of the lesson title.

Co-authored-by: Rotimi Best <rotimi-best@users.noreply.github.com>

* fix(course): show completion check on mobile bottom-nav title

Move the filled check from the lesson page heading to the right of
the active lesson title in the mobile bottom bar.

Co-authored-by: Rotimi Best <rotimi-best@users.noreply.github.com>

---------

packages/storybook/src/molecules/public-course/public-course.stories.svelte

@@ -124,6 +124,25 @@
   {/snippet}
 </Story>
 
+<Story name="Bottom nav · completed lesson">
+  {#snippet template()}
+    <div class="ui:relative ui:min-h-[200px] ui:bg-background">
+      <PublicCourse.PublicCourseBottomNav
+        positionLabel="2 / 6"
+        sublineLabel="Delving into Data Analysis with Pandas"
+        sublineComplete
+        hasPrev
+        hasNext
+        centerVariant="ring"
+        progressPercent={33}
+        onPrev={() => console.log('prev')}
+        onNext={() => console.log('next')}
+        onOpenSheet={() => console.log('open sheet')}
+      />
+    </div>
+  {/snippet}
+</Story>
+
 <Story name="Mobile sheet · collapse + long course">
   {#snippet template()}
     {@const activeSlug = 'module-10-lesson-4'}