feat: Introduce swipe navigation between new Chat and Sidebar components and establish initial multi-platform project structure.

packages/shared/src/index.css

@@ -701,7 +701,7 @@ body {
 }
 
 .date-divider span {
-  background-color: var(--bg-primary);
+  /* background-color: var(--bg-primary); */
   padding: 0 8px;
   color: var(--text-muted);
   font-size: 12px;
@@ -3288,12 +3288,40 @@ body {
     height: 100dvh;
     padding-bottom: env(safe-area-inset-bottom, 0px);
     box-sizing: border-box;
+    overflow: hidden;
+    display: block;
   }
 
-  /* Sidebar fills entire screen on mobile */
-  .is-mobile .sidebar {
+  /* Sliding tray for swipe navigation */
+  .mobile-swipe-tray {
+    display: flex;
+    flex-direction: row;
+    width: 200vw;
+    height: 100%;
+    touch-action: pan-y;
+    will-change: transform;
+  }
+
+  .mobile-swipe-panel {
     width: 100vw;
     min-width: 100vw;
+    height: 100%;
+    flex-shrink: 0;
+    overflow: hidden;
+    position: relative;
+    overscroll-behavior-x: none;
+  }
+
+  /* Disable pointer events on children during active swipe */
+  .mobile-swipe-tray.is-swiping .mobile-swipe-panel > * {
+    pointer-events: none;
+  }
+
+  /* Sidebar fills its panel on mobile */
+  .is-mobile .sidebar {
+    width: 100%;
+    min-width: 100%;
+    height: 100%;
   }
 
   /* Hide members list on mobile (also enforced in JS) */
@@ -3345,7 +3373,8 @@ body {
 
   /* Chat container takes full width */
   .is-mobile .chat-container {
-    width: 100vw;
+    width: 100%;
+    height: 100%;
   }
 
   /* Channel topic - hide on very small screens (also hidden via JS) */
@@ -3355,7 +3384,8 @@ body {
 
   /* FriendsView takes full width */
   .is-mobile .friends-view {
-    width: 100vw;
+    width: 100%;
+    height: 100%;
   }
 
   /* Search panel full-width on mobile */
@@ -3364,6 +3394,12 @@ body {
     right: 0;
     border-radius: 0;
   }
+
+}
+
+/* Remove border between server-list and channel-list on mobile */
+.is-mobile .server-list {
+  border-right: none;
 }
 
 /* ============================================