Images Phase 3+4: roll tile treatment to Latest, topic/tag feeds, Saved

Carry the brief's uniform card language (compact photo banner or flat topic-
colored placeholder) onto every feed grid — Latest, topic/tag/mood views, and
the account Saved grid — so the whole site is visually consistent. Same quality
gate and uniform sizing; the brief hero remains the single large image.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/routes/account/+page.svelte

@@ -115,7 +115,7 @@
       {:else if savedShown.length}
         <div class="grid">
           {#each savedShown as a (a.id)}
-            <ArticleCard article={a} onview={record} />
+            <ArticleCard article={a} thumb onview={record} />
           {/each}
         </div>
       {:else if savedReady}