Studies: add a Download Study Guide button to the study page, automatic from the linked series/book or chosen per study in admin; v2.35.0

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/AdminPage.tsx

@@ -6013,6 +6013,19 @@ const [dashboardNow, setDashboardNow] = useState(() => new Date())
                             <label htmlFor={`study-chapters-${activeStudy.id}`}>Number of Chapters</label>
                             <input id={`study-chapters-${activeStudy.id}`} type="number" min="1" max="999" value={activeStudy.numberOfChapters} placeholder="4" onChange={e => updateStudyProgram(activeStudy.id, 'numberOfChapters', Number(e.target.value) || 1)} />
                           </div>
+                          <div className="admin-field">
+                            <label htmlFor={`study-guide-source-${activeStudy.id}`}>Study Guide Download</label>
+                            <select id={`study-guide-source-${activeStudy.id}`} value={activeStudy.guideSource ?? ''} onChange={e => updateStudyProgram(activeStudy.id, 'guideSource', e.target.value)}>
+                              <option value="">Automatic (guide of the series or book linked to this study)</option>
+                              <option value="none">None — don&rsquo;t show a guide button</option>
+                              {form.studyGuideTitle && <option value="primary">Current series guide: {form.studyGuideTitle}</option>}
+                              {form.secondSeries?.guide?.title && <option value="second">Second series guide: {form.secondSeries.guide.title}</option>}
+                              {(form.finishedBooks ?? []).filter(b => b.guide?.title).map(b => (
+                                <option key={b.id} value={`book:${b.id}`}>{b.title}: {b.guide?.title}</option>
+                              ))}
+                            </select>
+                            <p className="admin-field-help">Adds a &ldquo;Download Study Guide&rdquo; button to this study&rsquo;s page. Visitors enter their name and email to get the file.</p>
+                          </div>
                           <div className="admin-field" style={{ display: 'flex', alignItems: 'center', gap: '0.6rem' }}>
                             <input id={`study-home-feature-${activeStudy.id}`} type="checkbox" checked={activeStudy.showOnHomepage === true} onChange={e => updateStudyProgram(activeStudy.id, 'showOnHomepage', e.target.checked)} />
                             <label htmlFor={`study-home-feature-${activeStudy.id}`}>Feature this study card on homepage</label>