Fix URL encoding for book names with spaces in index pages

Updated both commentary and cross-references index templates to use:
- Proper URL format: /book/{book}/chapter/{chapter}/verse/{verse}
- urlencode filter to handle spaces in book names (e.g., "1 Chronicles")

Previously used incorrect format /book/{book}/{chapter}:{verse} which
caused 422 errors for books with spaces in their names.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

kjvstudy_org/templates/commentary_index.html

@@ -26,7 +26,7 @@
             <strong>Chapter {{ chapter }}:</strong>
             <span class="verse-list">
                 {% for verse in verses %}
-                <a href="/book/{{ book }}/{{ chapter }}:{{ verse }}" class="verse-link">{{ verse }}</a>{% if not loop.last %},{% endif %}
+                <a href="/book/{{ book|urlencode }}/chapter/{{ chapter }}/verse/{{ verse }}" class="verse-link">{{ verse }}</a>{% if not loop.last %},{% endif %}
                 {% endfor %}
             </span>
             <span class="verse-count">({{ verses|length }} {% if verses|length == 1 %}verse{% else %}verses{% endif %})</span>

kjvstudy_org/templates/cross_references_index.html

@@ -27,7 +27,7 @@
             <strong>Chapter {{ chapter }}:</strong>
             <span class="verse-list">
                 {% for verse_data in verses %}
-                <a href="/book/{{ book|replace(' ', '_') }}/{{ chapter }}:{{ verse_data.verse }}" class="verse-link" title="{{ verse_data.ref_count }} cross-references">
+                <a href="/book/{{ book|urlencode }}/chapter/{{ chapter }}/verse/{{ verse_data.verse }}" class="verse-link" title="{{ verse_data.ref_count }} cross-references">
                     {{ verse_data.verse }}<span class="ref-badge">{{ verse_data.ref_count }}</span>
                 </a>{% if not loop.last %} {% endif %}
                 {% endfor %}