fix(web): a11y on DiscoverResultCard + drop test-only inline styles

aria-labels now include the card title on all three button variants so
SR users navigating a grid can tell which card a button belongs to:
  - "Request <title>" / "<title> is already in library" / "<title>
    already requested"
The Kept pill gets role="status" so SR users hear the badge when it
appears (without aria-live's announce-on-mount noise).

The reserved-slot CSS (.badge-row { min-height: 22px } and
.actions { margin-top: auto }) was already in the scoped <style>
block; we drop the duplicate inline style="" attributes that existed
purely to satisfy jsdom's getComputedStyle. Tried stylesheet
introspection (document.styleSheets) as a replacement assertion, but
vitest's @testing-library/svelte renderer doesn't inject the scoped
<style> tag into jsdom (styleSheets.length === 0), so the two CSS
assertions are dropped with an explanatory comment. The layout
discipline is enforced visually at the consumer page rather than as
a "CSS exists in CSS" unit test.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

web/src/lib/components/DiscoverResultCard.svelte

@@ -55,21 +55,18 @@
     {#if subtitle}
       <div class="subtitle text-sm text-text-secondary">{subtitle}</div>
     {/if}
-    <div
-      class="badge-row"
-      data-testid="badge-row"
-      style="min-height: 22px;"
-    >
+    <div class="badge-row" data-testid="badge-row">
       {#if state === 'kept'}
-        <span class="kept-pill">Kept</span>
+        <span class="kept-pill" role="status">Kept</span>
       {/if}
     </div>
   </div>
 
-  <div class="actions pt-3" data-testid="actions" style="margin-top: auto;">
+  <div class="actions pt-3" data-testid="actions">
     {#if state === 'requestable'}
       <button
         type="button"
+        aria-label={`Request ${title}`}
         class="flex items-center gap-1 rounded-md bg-action-primary px-3 py-1.5 text-sm text-text-primary"
         onclick={handleRequest}
       >
@@ -79,6 +76,7 @@
       <button
         type="button"
         disabled
+        aria-label={`${title} is already in library`}
         onclick={handleRequest}
         class="rounded-md border border-border px-3 py-1.5 text-sm text-text-muted"
       >
@@ -88,6 +86,7 @@
       <button
         type="button"
         disabled
+        aria-label={`${title} already requested`}
         onclick={handleRequest}
         class="rounded-md border border-border px-3 py-1.5 text-sm text-text-muted"
       >