feat(templates): Add microformats2 h-feed and p-category markup for tags

Implement Phase 2 of v1.3.0 per microformats-tags-design.md

Template Updates:
- templates/index.html: Add h-feed properties (u-url, enhanced p-author with u-photo/p-note, feed-level u-photo)
- templates/index.html: Add p-category markup with rel="tag" to note previews
- templates/note.html: Add p-category markup with rel="tag" for tags
- templates/note.html: Enhance author h-card with u-photo and p-note (hidden for parsers)
- templates/note.html: Document u-photo placement outside e-content per draft spec
- templates/tag.html: Create new tag archive template with h-feed structure

Key Decisions Applied:
- Tags ordered alphabetically by display_name (ready for backend)
- rel="tag" on all p-category links per microformats2 spec
- Author bio (p-note) hidden with display: none for semantic parsing
- Dual u-photo elements intentional for parser compatibility
- Graceful fallback when author photo/bio not available

Templates are backward compatible and ready for backend integration.

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

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

templates/index.html

@@ -5,15 +5,33 @@
 
 {% block content %}
 <div class="h-feed">
+  {# h-feed required properties per microformats.org/wiki/h-feed #}
   <h2 class="p-name">{{ config.SITE_NAME or 'Recent Notes' }}</h2>
 
-  {# Feed-level author h-card (per Q24) #}
+  {# u-url for feed (self-reference) #}
+  <a class="u-url" href="{{ url_for('public.index', _external=True) }}" style="display: none;">Feed URL</a>
+
+  {# Feed-level author h-card with all properties #}
+  {# Hidden because it's semantic-only markup for parsers, not visual content #}
+  {# The visible author display is on individual note pages #}
   {% if author %}
   <div class="p-author h-card" style="display: none;">
-    <a class="p-name u-url" href="{{ author.url or author.me }}">{{ author.name or author.url }}</a>
+    {% if author.photo %}
+    <img class="u-photo" src="{{ author.photo }}" alt="{{ author.name or 'Author' }}">
+    {% endif %}
+    <a class="p-name u-url" href="{{ author.url or author.me }}">{{ author.name or author.url or author.me }}</a>
+    {% if author.note %}
+    <p class="p-note">{{ author.note }}</p>
+    {% endif %}
   </div>
   {% endif %}
 
+  {# u-photo at feed level (duplicate of author photo for broad parser compatibility) #}
+  {# Some parsers expect feed-level u-photo, others look inside author h-card #}
+  {% if author and author.photo %}
+  <img class="u-photo" src="{{ author.photo }}" alt="" style="display: none;">
+  {% endif %}
+
   {% if notes %}
     {% for note in notes %}
     <article class="h-entry note-preview">
@@ -41,6 +59,15 @@
           </time>
         </a>
 
+        {# Tags in preview #}
+        {% if note.tags %}
+        <span class="note-tags">
+          {% for tag in note.tags %}
+          <a class="p-category" rel="tag" href="{{ url_for('public.tag', tag=tag.name) }}">{{ tag.display_name }}</a>
+          {% endfor %}
+        </span>
+        {% endif %}
+
         {# Author h-card nested in each h-entry (per Q20) #}
         {% if author %}
         <div class="p-author h-card">