Add version chip (v0.1.0) + changelog

- version.py: __version__ = 0.1.0 + structured CHANGELOG (newest first).
- footer version chip on every page (base.html) links to /changelog.
- /changelog page renders release notes; CHANGELOG.md mirrors it.
- 0.1.0 captures the storage/SQLite/settings/suggestions/backup work.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

templates/base.html

@@ -36,6 +36,12 @@
     {% endif %}
     {% block content %}{% endblock %}
   </main>
+  <footer style="text-align:center;padding:1.5rem 0 2.25rem;">
+    <a href="{{ url_for('changelog_view') }}" title="What's new"
+       style="display:inline-block;font-size:.75rem;color:#B0A89E;text-decoration:none;border:1px solid #EDE8E2;border-radius:999px;padding:.2rem .65rem;">
+      🌙 Moon Household Budget · v{{ app_version }}
+    </a>
+  </footer>
 <script>
 document.addEventListener('DOMContentLoaded', function () {
   // Wrap all number budget-inputs with a $ prefix and format on blur

templates/changelog.html

@@ -0,0 +1,19 @@
+{% extends "base.html" %}
+{% block content %}
+<div style="max-width:720px;">
+  <h1>📒 What's New</h1>
+  <p style="color:#7A6E68;margin-bottom:1.25rem;">Current version: <strong>v{{ app_version }}</strong></p>
+
+  {% for rel in changelog %}
+  <div style="border:1px solid #EDE8E2;border-radius:10px;padding:1rem 1.25rem;margin-bottom:1rem;">
+    <div style="display:flex;align-items:baseline;gap:.6rem;flex-wrap:wrap;">
+      <h2 style="margin:0;font-size:1.1rem;">v{{ rel.version }}</h2>
+      <span style="color:#B0A89E;font-size:.85rem;">{{ rel.date }}{% if rel.title %} · {{ rel.title }}{% endif %}</span>
+    </div>
+    <ul style="margin:.6rem 0 0;padding-left:1.2rem;">
+      {% for c in rel.changes %}<li style="margin:.3rem 0;">{{ c }}</li>{% endfor %}
+    </ul>
+  </div>
+  {% endfor %}
+</div>
+{% endblock %}