feat: add reactions, bookmarks, polls modules with session remember config

Add three new feature modules (reactions, bookmarks, polls) with corresponding database tables, indexes, and router registrations. Introduce `SESSION_MAX_AGE_REMEMBER` config for extended session duration, add `get_unread_messages` template global, and include operational defaults for rate limiting and session settings in `site_settings`.

devplacepy/templates/saved.html

@@ -0,0 +1,27 @@
+{% extends "base.html" %}
+{% block extra_head %}
+<link rel="stylesheet" href="/static/css/feed.css">
+<link rel="stylesheet" href="/static/css/post.css">
+{% endblock %}
+{% block content %}
+<div class="saved-page">
+    <h1 class="saved-title">Saved</h1>
+    <div class="saved-list">
+        {% for item in items %}
+        <a href="{{ item.url }}" class="saved-item">
+            <span class="saved-type badge">{{ item.type_label }}</span>
+            <span class="saved-item-title">{{ item.title }}</span>
+            <span class="saved-item-time">{{ item.time_ago }}</span>
+        </a>
+        {% else %}
+        <div class="empty-state">Nothing saved yet. Use the Save button on posts, gists, projects and news.</div>
+        {% endfor %}
+    </div>
+
+    {% if next_cursor %}
+    <div class="load-more-wrap">
+        <a href="/bookmarks/saved?before={{ next_cursor }}" class="btn btn-secondary">Load more</a>
+    </div>
+    {% endif %}
+</div>
+{% endblock %}