Auth endpoint

The IndieAuth endpoint should be added, currently adding the unt tests

public/assets/css/app.css

@@ -5,3 +5,4 @@
 @import url('code.css');
 @import url('content.css');
 @import url('notes.css');
+@import url('indieauth.css');

public/assets/css/indieauth.css

@@ -0,0 +1,15 @@
+.indieauth {
+  .error {
+    color: var(--color-danger);
+    background-color: var(--color-danger-shadow);
+    border: 1px solid var(--color-danger);
+    border-radius: .5rem;
+
+    display: flex;
+    padding-inline: 1rem;
+    padding-block: .5rem;
+    width: fit-content;
+
+    margin-block-end: 1rem;
+  }
+}

public/assets/css/variables.css

@@ -20,4 +20,6 @@
   --color-link-visited: oklch(70.44% 0.21 304.41deg);
   --color-primary-shadow: oklch(19.56% 0.054 125.505deg / 40%);
   --rss-color-link: oklch(67.59% 0.189 42.04deg);
+  --color-danger: oklch(64.41% 0.281 23.29deg);
+  --color-danger-shadow: oklch(64.41% 0.281 23.29deg / 10%);
 }