fix: point footer about link at about.html (#59)

index.html

@@ -680,7 +680,7 @@ html, body {
 
   <!-- Footer -->
   <footer id="footer">
-    <a href="/about" aria-label="About The Door">about</a>
+    <a href="/about.html" aria-label="About The Door">about</a>
     <button id="safety-plan-btn" aria-label="Open My Safety Plan">my safety plan</button>
     <button id="clear-chat-btn" aria-label="Clear chat history">clear chat</button>
   </footer>

tests/test_about_link.py

@@ -0,0 +1,24 @@
+import pathlib
+import unittest
+
+
+ROOT = pathlib.Path(__file__).resolve().parents[1]
+INDEX_HTML = ROOT / 'index.html'
+ABOUT_HTML = ROOT / 'about.html'
+
+
+class TestAboutLink(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.html = INDEX_HTML.read_text(encoding='utf-8')
+
+    def test_about_page_exists(self):
+        self.assertTrue(ABOUT_HTML.exists(), 'about.html should exist for static serving')
+
+    def test_footer_about_link_targets_static_about_html(self):
+        self.assertIn('href="/about.html"', self.html)
+        self.assertNotIn('href="/about"', self.html)
+
+
+if __name__ == '__main__':
+    unittest.main()