feat(corpus): make source links visible on search result cards

- a.passage-card__title now shows teal+underline (was ink/no-decoration, undetectable)
- adds "View source ↗" link below each passage excerpt when source_url present

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

assets/css/tools.css

@@ -3529,6 +3529,19 @@ a.dr-source-title-link:hover {
   margin-bottom: 6px;
 }
 .passage-card__title:hover { color: var(--teal); text-decoration: underline; }
+a.passage-card__title { color: var(--teal); text-decoration: underline; text-underline-offset: 2px; }
+a.passage-card__title:hover { color: var(--ink); }
+
+.passage-source-link {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  font-size: 0.76rem;
+  color: var(--muted);
+  text-decoration: none;
+  margin-top: 8px;
+}
+.passage-source-link:hover { color: var(--teal); text-decoration: underline; }
 
 .passage-card__excerpt {
   font-size: 0.82rem;

corpus.php

@@ -798,6 +798,9 @@ require_once __DIR__ . '/includes/layout.php';
                 const excerpt  = highlight(hit.excerpt || '', q);
                 const fullText  = (hit.full_text || '').trim();
                 const hasMore   = fullText.length > (hit.excerpt || '').length;
+                const sourceLink = hit.source_url
+                    ? `<a href="${esc(hit.source_url)}" target="_blank" rel="noopener" class="passage-source-link">View source ↗</a>`
+                    : '';
 
                 const card = document.createElement('div');
                 card.className = 'passage-card';
@@ -809,6 +812,7 @@ require_once __DIR__ . '/includes/layout.php';
                     </div>
                     ${titleHtml}
                     <p class="passage-card__excerpt">${excerpt}</p>
+                    ${sourceLink}
                     ${hasMore ? '<button class="passage-expand-btn" type="button" aria-expanded="false">Show full passage</button><div class="passage-full-text" hidden></div>' : ''}`;
 
                 if (hasMore) {