Refactor app menu sidebar

* Rename to "app menu" across code
* Move content to dedicated sections/components, introduce app menu links
* Use CSS variable for hover background color across the app

app/styles/app.css

@@ -2,6 +2,7 @@
 
 :root {
   --default-list-color: #fc3;
+  --hover-bg: #f8f9fa;
 }
 
 html,
@@ -251,10 +252,43 @@ body {
   overscroll-behavior: contain;
 }
 
+.app-menu {
+  list-style: none;
+  padding: 0;
+  margin: 0 -1rem;
+}
+
+.app-menu button {
+  width: 100%;
+  display: flex;
+  align-items: center;
+  gap: 0.8rem;
+  padding: 1rem;
+  padding-left: 1.4rem;
+  background: none;
+  border: none;
+  color: #333;
+  cursor: pointer;
+  text-align: left;
+  font-size: 0.95rem;
+  font-family: inherit;
+  transition: background-color 0.2s;
+}
+
+.app-menu button:hover {
+  background-color: var(--hover-bg);
+}
+
+.app-menu .icon {
+  color: #666;
+  width: 20px;
+  height: 20px;
+}
+
 .edit-form {
   margin: -1rem;
   margin-bottom: 1rem;
-  background: #f8f9fa;
+  background: var(--hover-bg);
   padding: 1rem;
   border-bottom: 1px solid #eee;
 }
@@ -276,7 +310,7 @@ body {
   border: 1px solid #ddd;
   border-radius: 4px;
   font-family: inherit;
-  font-size: 1rem;
+  font-size: 0.95rem;
   box-sizing: border-box; /* Ensure padding doesn't overflow width */
 }
 
@@ -294,15 +328,7 @@ body {
 
 .settings-section {
   margin-bottom: 2rem;
-}
-
-.settings-section h3 {
-  font-size: 1rem;
-  font-weight: bold;
-  color: #666;
-  margin: 0 0 0.5rem;
-  text-transform: uppercase;
-  letter-spacing: 0.5px;
+  font-size: 0.95rem;
 }
 
 .settings-section .form-group {
@@ -400,7 +426,7 @@ body {
 }
 
 .place-item:hover {
-  background: #eee;
+  background: var(--hover-bg);
 }
 
 .place-name {
@@ -946,7 +972,7 @@ button.create-place {
 
 .search-result-item:hover,
 .search-result-item:focus {
-  background: #f5f5f5;
+  background: var(--hover-bg);
   outline: none;
 }
 
@@ -1011,7 +1037,7 @@ button.create-place {
 }
 
 .place-lists-manager .list-item:hover {
-  background: #f8f9fa;
+  background: var(--hover-bg);
 }
 
 .place-lists-manager label {