diff --git a/mobile/src/api/chat.ts b/mobile/src/api/chat.ts
index 1d1fbf4..ab86e55 100644
--- a/mobile/src/api/chat.ts
+++ b/mobile/src/api/chat.ts
@@ -19,12 +19,26 @@ export interface TokenUsage {
   trimmed?: boolean;
 }
 
+export interface ContextFile {
+  name: string;
+  content: string;
+}
+
+export interface BranchNode {
+  id: string;
+  role: string;
+  content_preview: string;
+  is_active: boolean;
+  children: BranchNode[];
+}
+
 export interface ChatSession {
   id: string;
   title: string;
   messages: ChatMessage[];
   system_prompt?: string;
   source?: string | null;
+  context_files?: ContextFile[];
   created: string;
   updated: string;
   token_usage?: TokenUsage;
@@ -75,6 +89,41 @@ export const chatApi = {
   deleteSession: (id: string) =>
     api.delete<{ status: string }>(`/admin/chat/sessions/${id}`),
 
+  updateSession: (
+    id: string,
+    data: {
+      title?: string;
+      system_prompt?: string;
+      context_files?: ContextFile[];
+    },
+  ) =>
+    api.put<{ session: ChatSession }>(
+      `/admin/chat/sessions/${id}`,
+      data,
+    ),
+
+  deleteMessage: (sessionId: string, messageId: string) =>
+    api.delete<{ status: string }>(
+      `/admin/chat/sessions/${sessionId}/messages/${messageId}`,
+    ),
+
+  // Branches
+  getBranches: (sessionId: string) =>
+    api.get<{ branches: BranchNode[] }>(
+      `/admin/chat/sessions/${sessionId}/branches`,
+    ),
+
+  switchBranch: (sessionId: string, messageId: string) =>
+    api.post<{ status: string; session: ChatSession }>(
+      `/admin/chat/sessions/${sessionId}/branches/switch`,
+      { message_id: messageId },
+    ),
+
+  newBranch: (sessionId: string) =>
+    api.post<{ status: string; session: ChatSession }>(
+      `/admin/chat/sessions/${sessionId}/branches/new`,
+    ),
+
   streamMessage: (
     sessionId: string,
     content: string,
diff --git a/mobile/src/views/ChatListView.vue b/mobile/src/views/ChatListView.vue
index 8042e65..e591795 100644
--- a/mobile/src/views/ChatListView.vue
+++ b/mobile/src/views/ChatListView.vue
@@ -27,15 +27,6 @@ async function loadSessions() {
   }
 }
 
-async function createChat() {
-  try {
-    const data = await chatApi.createSession();
-    router.push(`/chat/${data.session.id}`);
-  } catch (e) {
-    error.value = e instanceof Error ? e.message : "Failed to create";
-  }
-}
-
 function openChat(id: string) {
   router.push(`/chat/${id}`);
 }
@@ -196,25 +187,5 @@ onMounted(loadSessions);
       </div>
     </div>
 
-    <!-- FAB -->
-    <button
-      class="absolute bottom-6 right-6 w-14 h-14 rounded-full bg-amber-600 hover:bg-amber-700 shadow-lg shadow-amber-900/50 flex items-center justify-center transition-colors active:scale-95"
-      @click="createChat"
-    >
-      <svg
-        xmlns="http://www.w3.org/2000/svg"
-        width="24"
-        height="24"
-        viewBox="0 0 24 24"
-        fill="none"
-        stroke="white"
-        stroke-width="2"
-        stroke-linecap="round"
-        stroke-linejoin="round"
-      >
-        <line x1="12" y1="5" x2="12" y2="19" />
-        <line x1="5" y1="12" x2="19" y2="12" />
-      </svg>
-    </button>
   </div>
 </template>
diff --git a/mobile/src/views/ChatView.vue b/mobile/src/views/ChatView.vue
index 11d6bc1..94867fd 100644
--- a/mobile/src/views/ChatView.vue
+++ b/mobile/src/views/ChatView.vue
@@ -1,7 +1,13 @@
 <script setup lang="ts">
-import { ref, computed, onMounted, nextTick, watch } from "vue";
+import { ref, computed, onMounted, onUnmounted, nextTick, watch } from "vue";
 import { useRoute, useRouter } from "vue-router";
-import { chatApi, type ChatMessage, type StreamChunk } from "@/api/chat";
+import {
+  chatApi,
+  type ChatMessage,
+  type StreamChunk,
+  type BranchNode,
+  type ContextFile,
+} from "@/api/chat";
 import { useTts } from "@/composables/useTts";
 import MessageBubble from "@/components/MessageBubble.vue";
 import ChatInput from "@/components/ChatInput.vue";
@@ -19,8 +25,58 @@ const streamingContent = ref("");
 const error = ref<string | null>(null);
 const messagesContainer = ref<HTMLElement | null>(null);
 
+// Panels
+const showBranches = ref(false);
+const showContextFiles = ref(false);
+const branches = ref<BranchNode[]>([]);
+const contextFiles = ref<ContextFile[]>([]);
+const branchesLoading = ref(false);
+const contextFileInputRef = ref<HTMLInputElement | null>(null);
+
+// Resizable panel height (portrait) / width (landscape)
+const panelSize = ref(200);
+const isResizing = ref(false);
+const resizeStartPos = ref(0);
+const resizeStartSize = ref(0);
+
+// Orientation
+const isLandscape = ref(false);
+function updateOrientation() {
+  isLandscape.value = window.innerWidth > window.innerHeight;
+}
+
 let abortStream: (() => void) | null = null;
 
+// === Resize handle ===
+
+function onResizeStart(e: TouchEvent | MouseEvent) {
+  isResizing.value = true;
+  const pos = "touches" in e ? e.touches[0]! : e;
+  resizeStartPos.value = isLandscape.value ? pos.clientX : pos.clientY;
+  resizeStartSize.value = panelSize.value;
+  e.preventDefault();
+}
+
+function onResizeMove(e: TouchEvent | MouseEvent) {
+  if (!isResizing.value) return;
+  const pos = "touches" in e ? e.touches[0]! : e;
+  if (isLandscape.value) {
+    // Dragging left edge → increasing width = startX - currentX
+    const delta = resizeStartPos.value - pos.clientX;
+    panelSize.value = Math.max(150, Math.min(window.innerWidth * 0.7, resizeStartSize.value + delta));
+  } else {
+    // Dragging bottom edge → increasing height
+    const delta = pos.clientY - resizeStartPos.value;
+    panelSize.value = Math.max(100, Math.min(window.innerHeight * 0.6, resizeStartSize.value + delta));
+  }
+}
+
+function onResizeEnd() {
+  isResizing.value = false;
+}
+
+// === Session ===
+
 async function loadSession() {
   isLoading.value = true;
   error.value = null;
@@ -30,6 +86,7 @@ async function loadSession() {
     messages.value = data.session.messages.filter(
       (m) => m.is_active !== false,
     );
+    contextFiles.value = data.session.context_files || [];
     await scrollToBottom();
   } catch (e) {
     error.value = e instanceof Error ? e.message : "Failed to load";
@@ -39,7 +96,6 @@ async function loadSession() {
 }
 
 async function sendMessage(content: string) {
-  // Add user message optimistically
   const userMsg: ChatMessage = {
     id: "temp-" + Date.now(),
     role: "user",
@@ -49,7 +105,6 @@ async function sendMessage(content: string) {
   messages.value.push(userMsg);
   await scrollToBottom();
 
-  // Start streaming
   isStreaming.value = true;
   streamingContent.value = "";
 
@@ -64,7 +119,6 @@ async function sendMessage(content: string) {
           break;
         case "assistant_message":
           if (chunk.message) {
-            // Replace temp user message with real one if available
             messages.value.push(chunk.message);
             streamingContent.value = "";
             isStreaming.value = false;
@@ -73,7 +127,6 @@ async function sendMessage(content: string) {
           break;
         case "user_message":
           if (chunk.message) {
-            // Replace optimistic user message
             const idx = messages.value.findIndex(
               (m) => m.id === userMsg.id,
             );
@@ -116,6 +169,12 @@ function stopStreaming() {
   }
 }
 
+function scrollToTop() {
+  if (messagesContainer.value) {
+    messagesContainer.value.scrollTo({ top: 0, behavior: "smooth" });
+  }
+}
+
 async function scrollToBottom() {
   await nextTick();
   if (messagesContainer.value) {
@@ -124,120 +183,478 @@ async function scrollToBottom() {
   }
 }
 
-// Watch streaming content for auto-scroll
+// === Branches ===
+
+async function loadBranches() {
+  branchesLoading.value = true;
+  try {
+    const data = await chatApi.getBranches(sessionId.value);
+    branches.value = data.branches;
+  } catch {
+    branches.value = [];
+  } finally {
+    branchesLoading.value = false;
+  }
+}
+
+function toggleBranches() {
+  showContextFiles.value = false;
+  showBranches.value = !showBranches.value;
+  if (showBranches.value) loadBranches();
+}
+
+async function switchBranch(messageId: string) {
+  try {
+    const data = await chatApi.switchBranch(sessionId.value, messageId);
+    if (data.session) {
+      messages.value = data.session.messages.filter(
+        (m) => m.is_active !== false,
+      );
+      title.value = data.session.title || "Chat";
+    }
+    await loadBranches();
+    await scrollToBottom();
+  } catch (e) {
+    error.value = e instanceof Error ? e.message : "Failed to switch";
+  }
+}
+
+async function createNewBranch() {
+  try {
+    const data = await chatApi.newBranch(sessionId.value);
+    if (data.session) {
+      messages.value = data.session.messages.filter(
+        (m) => m.is_active !== false,
+      );
+    }
+    if (showBranches.value) await loadBranches();
+    await scrollToBottom();
+  } catch (e) {
+    error.value = e instanceof Error ? e.message : "Failed to create branch";
+  }
+}
+
+async function deleteBranch() {
+  const activeMessages = messages.value;
+  if (!activeMessages.length) {
+    error.value = "No messages to delete";
+    return;
+  }
+  if (!confirm("Delete current branch? All messages will be removed from the server.")) return;
+  try {
+    for (let i = activeMessages.length - 1; i >= 0; i--) {
+      const m = activeMessages[i]!;
+      if (!m.id.startsWith("temp-") && !m.id.startsWith("partial-")) {
+        await chatApi.deleteMessage(sessionId.value, m.id);
+      }
+    }
+    messages.value = [];
+    if (showBranches.value) await loadBranches();
+  } catch (e) {
+    error.value = e instanceof Error ? e.message : "Failed to delete";
+    await loadSession();
+  }
+}
+
+function flattenBranches(
+  nodes: BranchNode[],
+  depth = 0,
+): { node: BranchNode; depth: number }[] {
+  const result: { node: BranchNode; depth: number }[] = [];
+  for (const n of nodes) {
+    result.push({ node: n, depth });
+    if (n.children?.length) {
+      result.push(...flattenBranches(n.children, depth + 1));
+    }
+  }
+  return result;
+}
+
+const flatBranches = computed(() => flattenBranches(branches.value));
+
+// === Context Files ===
+
+function toggleContextFiles() {
+  showBranches.value = false;
+  showContextFiles.value = !showContextFiles.value;
+}
+
+function triggerFileUpload() {
+  contextFileInputRef.value?.click();
+}
+
+function handleFileUpload(event: Event) {
+  const input = event.target as HTMLInputElement;
+  if (!input.files) return;
+  const files = Array.from(input.files);
+  let loaded = 0;
+  files.forEach((file) => {
+    const reader = new FileReader();
+    reader.onload = (e) => {
+      const content = e.target?.result as string;
+      contextFiles.value.push({ name: file.name, content });
+      loaded++;
+      if (loaded === files.length) saveContextFiles();
+    };
+    reader.readAsText(file);
+  });
+  input.value = "";
+}
+
+function removeContextFile(index: number) {
+  contextFiles.value.splice(index, 1);
+  saveContextFiles();
+}
+
+async function saveContextFiles() {
+  try {
+    await chatApi.updateSession(sessionId.value, {
+      context_files: contextFiles.value,
+    });
+  } catch (e) {
+    error.value = e instanceof Error ? e.message : "Failed to save files";
+  }
+}
+
+const anyPanelOpen = computed(() => showBranches.value || showContextFiles.value);
+
+function closePanel() {
+  showBranches.value = false;
+  showContextFiles.value = false;
+}
+
 watch(streamingContent, () => {
   scrollToBottom();
 });
 
-onMounted(loadSession);
+onMounted(() => {
+  loadSession();
+  updateOrientation();
+  window.addEventListener("resize", updateOrientation);
+  window.addEventListener("mousemove", onResizeMove);
+  window.addEventListener("mouseup", onResizeEnd);
+  window.addEventListener("touchmove", onResizeMove, { passive: false });
+  window.addEventListener("touchend", onResizeEnd);
+});
+
+onUnmounted(() => {
+  window.removeEventListener("resize", updateOrientation);
+  window.removeEventListener("mousemove", onResizeMove);
+  window.removeEventListener("mouseup", onResizeEnd);
+  window.removeEventListener("touchmove", onResizeMove);
+  window.removeEventListener("touchend", onResizeEnd);
+});
 </script>
 
 <template>
-  <div class="h-full flex flex-col">
-    <!-- Header -->
-    <div
-      class="shrink-0 flex items-center gap-3 px-4 py-3 border-b border-stone-800 bg-stone-950/95 backdrop-blur"
-    >
-      <button
-        class="text-stone-400 hover:text-white transition-colors"
-        @click="router.back()"
+  <div class="h-full flex" :class="isLandscape ? 'flex-row' : 'flex-col'">
+    <!-- Main chat area -->
+    <div class="flex-1 flex flex-col min-w-0 min-h-0">
+      <!-- Header -->
+      <div
+        class="shrink-0 flex items-center gap-2 px-3 py-2.5 border-b border-stone-800 bg-stone-950/95 backdrop-blur"
       >
-        <svg
-          xmlns="http://www.w3.org/2000/svg"
-          width="20"
-          height="20"
-          viewBox="0 0 24 24"
-          fill="none"
-          stroke="currentColor"
-          stroke-width="2"
-          stroke-linecap="round"
-          stroke-linejoin="round"
+        <button
+          class="text-stone-400 hover:text-white transition-colors"
+          @click="router.back()"
         >
-          <polyline points="15 18 9 12 15 6" />
-        </svg>
-      </button>
-      <h1 class="text-sm font-medium text-white truncate flex-1">
-        {{ title }}
-      </h1>
-    </div>
+          <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <polyline points="15 18 9 12 15 6" />
+          </svg>
+        </button>
+        <h1 class="text-sm font-medium text-white truncate flex-1">
+          {{ title }}
+        </h1>
 
-    <!-- Messages -->
-    <div
-      ref="messagesContainer"
-      class="flex-1 overflow-y-auto py-4"
-    >
-      <!-- Loading -->
-      <div
-        v-if="isLoading"
-        class="flex items-center justify-center h-32"
-      >
-        <div
-          class="w-6 h-6 border-2 border-amber-500 border-t-transparent rounded-full animate-spin"
-        />
-      </div>
+        <!-- Toolbar buttons -->
+        <button
+          class="p-1.5 rounded-lg transition-colors"
+          :class="showContextFiles ? 'bg-amber-600/20 text-amber-400' : 'text-stone-400 hover:text-white'"
+          title="Context files"
+          @click="toggleContextFiles"
+        >
+          <svg xmlns="http://www.w3.org/2000/svg" width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <path d="m21.44 11.05-9.19 9.19a6 6 0 0 1-8.49-8.49l8.57-8.57A4 4 0 1 1 18 8.84l-8.59 8.57a2 2 0 0 1-2.83-2.83l8.49-8.48" />
+          </svg>
+        </button>
 
-      <!-- Error -->
-      <div
-        v-if="error"
-        class="mx-4 mb-3 p-3 rounded-xl bg-red-900/30 border border-red-800/50 text-red-400 text-sm"
-      >
-        {{ error }}
+        <button
+          class="p-1.5 rounded-lg transition-colors"
+          :class="showBranches ? 'bg-amber-600/20 text-amber-400' : 'text-stone-400 hover:text-white'"
+          title="Branch tree"
+          @click="toggleBranches"
+        >
+          <svg xmlns="http://www.w3.org/2000/svg" width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <line x1="6" y1="3" x2="6" y2="15" />
+            <circle cx="18" cy="6" r="3" />
+            <circle cx="6" cy="18" r="3" />
+            <path d="M18 9a9 9 0 0 1-9 9" />
+          </svg>
+        </button>
+
+        <button
+          class="p-1.5 rounded-lg text-stone-400 hover:text-white transition-colors"
+          title="New branch"
+          @click="createNewBranch"
+        >
+          <svg xmlns="http://www.w3.org/2000/svg" width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <line x1="12" y1="5" x2="12" y2="19" />
+            <line x1="5" y1="12" x2="19" y2="12" />
+          </svg>
+        </button>
+
+        <button
+          class="p-1.5 rounded-lg text-stone-400 hover:text-red-400 transition-colors"
+          title="Delete branch"
+          @click="deleteBranch"
+        >
+          <svg xmlns="http://www.w3.org/2000/svg" width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <polyline points="3 6 5 6 21 6" />
+            <path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2" />
+          </svg>
+        </button>
       </div>
 
-      <!-- Message list -->
-      <template v-if="!isLoading">
-        <MessageBubble
-          v-for="msg in messages"
-          :key="msg.id"
-          :message="msg"
-          :is-speaking="tts.speakingMessageId.value === msg.id"
-          @speak="tts.speak($event, msg.id)"
-          @stop-speak="tts.stop()"
-        />
-
-        <!-- Streaming message -->
-        <MessageBubble
-          v-if="isStreaming && streamingContent"
-          :message="{
-            id: 'streaming',
-            role: 'assistant',
-            content: streamingContent,
-            timestamp: new Date().toISOString(),
-          }"
-          :is-streaming="true"
-        />
-
-        <!-- Typing indicator -->
+      <!-- Portrait: panel drops down below header -->
+      <template v-if="!isLandscape && anyPanelOpen">
+        <!-- Panel content -->
         <div
-          v-if="isStreaming && !streamingContent"
-          class="flex justify-start px-4 mb-3"
+          class="shrink-0 bg-stone-900/95 border-b border-stone-700 overflow-y-auto"
+          :style="{ height: panelSize + 'px' }"
         >
-          <div
-            class="bg-stone-800 rounded-2xl rounded-bl-md px-4 py-3 flex gap-1"
-          >
-            <div
-              class="w-2 h-2 rounded-full bg-slate-500 animate-bounce"
-              style="animation-delay: 0ms"
-            />
-            <div
-              class="w-2 h-2 rounded-full bg-slate-500 animate-bounce"
-              style="animation-delay: 150ms"
+          <!-- Branch Tree -->
+          <template v-if="showBranches">
+            <div class="px-3 py-2 text-xs font-medium text-stone-400 uppercase tracking-wide">
+              Branch Tree
+            </div>
+            <div v-if="branchesLoading" class="flex justify-center py-4">
+              <div class="w-5 h-5 border-2 border-amber-500 border-t-transparent rounded-full animate-spin" />
+            </div>
+            <div v-else-if="!flatBranches.length" class="px-3 py-3 text-sm text-stone-500">
+              No branches yet
+            </div>
+            <div v-else class="pb-2 overflow-x-auto">
+              <div class="min-w-max">
+                <button
+                  v-for="{ node, depth } in flatBranches"
+                  :key="node.id"
+                  class="w-full text-left px-3 py-1.5 text-xs hover:bg-stone-800/50 transition-colors flex items-center gap-1.5 whitespace-nowrap"
+                  :class="node.is_active ? 'text-amber-400' : 'text-stone-400'"
+                  :style="{ paddingLeft: `${12 + depth * 16}px` }"
+                  @click="switchBranch(node.id)"
+                >
+                  <span class="shrink-0">
+                    <svg v-if="node.role === 'user'" xmlns="http://www.w3.org/2000/svg" width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                      <path d="M20 21v-2a4 4 0 0 0-4-4H8a4 4 0 0 0-4 4v2" /><circle cx="12" cy="7" r="4" />
+                    </svg>
+                    <svg v-else xmlns="http://www.w3.org/2000/svg" width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                      <path d="M12 2a8 8 0 0 0-8 8c0 3.5 2 6 5 7.5V21h6v-3.5c3-1.5 5-4 5-7.5a8 8 0 0 0-8-8z" />
+                    </svg>
+                  </span>
+                  <span>{{ node.content_preview || '...' }}</span>
+                  <span v-if="node.is_active" class="shrink-0 text-[10px] bg-amber-600/30 text-amber-400 px-1 rounded">active</span>
+                </button>
+              </div>
+            </div>
+          </template>
+
+          <!-- Context Files -->
+          <template v-if="showContextFiles">
+            <div class="px-3 py-2 flex items-center justify-between">
+              <span class="text-xs font-medium text-stone-400 uppercase tracking-wide">
+                Context Files ({{ contextFiles.length }})
+              </span>
+              <button class="text-xs text-amber-400 hover:text-amber-300 transition-colors" @click="triggerFileUpload">
+                + Add file
+              </button>
+            </div>
+            <input ref="contextFileInputRef" type="file" multiple accept=".txt,.md,.json,.csv,.xml,.yaml,.yml,.log,.py,.js,.ts,.html,.css" class="hidden" @change="handleFileUpload" />
+            <div v-if="!contextFiles.length" class="px-3 py-3 text-sm text-stone-500">No files attached</div>
+            <div v-else class="pb-2">
+              <div v-for="(file, index) in contextFiles" :key="index" class="flex items-center gap-2 px-3 py-1.5 hover:bg-stone-800/50">
+                <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" class="text-stone-500 shrink-0">
+                  <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z" /><polyline points="14 2 14 8 20 8" />
+                </svg>
+                <span class="text-xs text-stone-300 truncate flex-1">{{ file.name }}</span>
+                <span class="text-[10px] text-stone-500">{{ Math.round(file.content.length / 1024) || '<1' }}KB</span>
+                <button class="text-stone-500 hover:text-red-400 transition-colors" @click="removeContextFile(index)">
+                  <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                    <line x1="18" y1="6" x2="6" y2="18" /><line x1="6" y1="6" x2="18" y2="18" />
+                  </svg>
+                </button>
+              </div>
+            </div>
+          </template>
+        </div>
+
+        <!-- Resize handle (portrait: horizontal bar at bottom of panel) -->
+        <div
+          class="shrink-0 h-3 flex items-center justify-center cursor-row-resize bg-stone-900/80 border-b border-stone-700 touch-none select-none"
+          @mousedown="onResizeStart"
+          @touchstart="onResizeStart"
+        >
+          <div class="w-10 h-1 rounded-full bg-stone-600" />
+        </div>
+      </template>
+
+      <!-- Messages wrapper (relative for scroll buttons) -->
+      <div class="flex-1 relative min-h-0">
+        <div
+          ref="messagesContainer"
+          class="absolute inset-0 overflow-y-auto py-4"
+        >
+          <div v-if="isLoading" class="flex items-center justify-center h-32">
+            <div class="w-6 h-6 border-2 border-amber-500 border-t-transparent rounded-full animate-spin" />
+          </div>
+
+          <div v-if="error" class="mx-4 mb-3 p-3 rounded-xl bg-red-900/30 border border-red-800/50 text-red-400 text-sm">
+            {{ error }}
+            <button class="ml-2 underline text-xs" @click="error = null">dismiss</button>
+          </div>
+
+          <template v-if="!isLoading">
+            <MessageBubble
+              v-for="msg in messages"
+              :key="msg.id"
+              :message="msg"
+              :is-speaking="tts.speakingMessageId.value === msg.id"
+              @speak="tts.speak($event, msg.id)"
+              @stop-speak="tts.stop()"
             />
-            <div
-              class="w-2 h-2 rounded-full bg-slate-500 animate-bounce"
-              style="animation-delay: 300ms"
+
+            <MessageBubble
+              v-if="isStreaming && streamingContent"
+              :message="{ id: 'streaming', role: 'assistant', content: streamingContent, timestamp: new Date().toISOString() }"
+              :is-streaming="true"
             />
-          </div>
+
+            <div v-if="isStreaming && !streamingContent" class="flex justify-start px-4 mb-3">
+              <div class="bg-stone-800 rounded-2xl rounded-bl-md px-4 py-3 flex gap-1">
+                <div class="w-2 h-2 rounded-full bg-slate-500 animate-bounce" style="animation-delay: 0ms" />
+                <div class="w-2 h-2 rounded-full bg-slate-500 animate-bounce" style="animation-delay: 150ms" />
+                <div class="w-2 h-2 rounded-full bg-slate-500 animate-bounce" style="animation-delay: 300ms" />
+              </div>
+            </div>
+          </template>
         </div>
-      </template>
+
+        <!-- Scroll buttons -->
+        <div class="absolute right-2 top-1/2 -translate-y-1/2 z-10 flex flex-col gap-1.5">
+          <button
+            class="p-2 rounded-full bg-stone-800/80 backdrop-blur border border-stone-700 shadow-md text-stone-400 hover:text-white active:bg-stone-700 transition-colors"
+            @click="scrollToTop"
+          >
+            <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+              <line x1="12" y1="5" x2="12" y2="19" />
+              <polyline points="5 12 12 5 19 12" />
+              <line x1="5" y1="3" x2="19" y2="3" />
+            </svg>
+          </button>
+          <button
+            class="p-2 rounded-full bg-stone-800/80 backdrop-blur border border-stone-700 shadow-md text-stone-400 hover:text-white active:bg-stone-700 transition-colors"
+            @click="scrollToBottom"
+          >
+            <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+              <line x1="12" y1="5" x2="12" y2="19" />
+              <polyline points="5 12 12 19 19 12" />
+              <line x1="5" y1="21" x2="19" y2="21" />
+            </svg>
+          </button>
+        </div>
+      </div>
+
+      <!-- Input -->
+      <ChatInput
+        :disabled="isLoading"
+        :is-streaming="isStreaming"
+        @send="sendMessage"
+        @stop="stopStreaming"
+      />
     </div>
 
-    <!-- Input -->
-    <ChatInput
-      :disabled="isLoading"
-      :is-streaming="isStreaming"
-      @send="sendMessage"
-      @stop="stopStreaming"
-    />
+    <!-- Landscape: side panel slides from right -->
+    <template v-if="isLandscape && anyPanelOpen">
+      <!-- Resize handle (vertical bar on left edge of panel) -->
+      <div
+        class="shrink-0 w-3 flex items-center justify-center cursor-col-resize bg-stone-900/80 border-l border-stone-700 touch-none select-none"
+        @mousedown="onResizeStart"
+        @touchstart="onResizeStart"
+      >
+        <div class="h-10 w-1 rounded-full bg-stone-600" />
+      </div>
+
+      <div
+        class="shrink-0 bg-stone-900/95 border-l border-stone-700 overflow-y-auto flex flex-col"
+        :style="{ width: panelSize + 'px' }"
+      >
+        <!-- Panel header with close -->
+        <div class="shrink-0 flex items-center justify-between px-3 py-2 border-b border-stone-800">
+          <span class="text-xs font-medium text-stone-400 uppercase tracking-wide">
+            {{ showBranches ? 'Branch Tree' : 'Context Files' }}
+          </span>
+          <button class="text-stone-500 hover:text-white transition-colors" @click="closePanel">
+            <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+              <line x1="18" y1="6" x2="6" y2="18" /><line x1="6" y1="6" x2="18" y2="18" />
+            </svg>
+          </button>
+        </div>
+
+        <!-- Branch Tree (landscape) -->
+        <template v-if="showBranches">
+          <div v-if="branchesLoading" class="flex justify-center py-4">
+            <div class="w-5 h-5 border-2 border-amber-500 border-t-transparent rounded-full animate-spin" />
+          </div>
+          <div v-else-if="!flatBranches.length" class="px-3 py-3 text-sm text-stone-500">No branches yet</div>
+          <div v-else class="flex-1 overflow-y-auto overflow-x-auto pb-2">
+            <div class="min-w-max">
+              <button
+                v-for="{ node, depth } in flatBranches"
+                :key="node.id"
+                class="w-full text-left px-3 py-1.5 text-xs hover:bg-stone-800/50 transition-colors flex items-center gap-1.5 whitespace-nowrap"
+                :class="node.is_active ? 'text-amber-400' : 'text-stone-400'"
+                :style="{ paddingLeft: `${12 + depth * 16}px` }"
+                @click="switchBranch(node.id)"
+              >
+                <span class="shrink-0">
+                  <svg v-if="node.role === 'user'" xmlns="http://www.w3.org/2000/svg" width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                    <path d="M20 21v-2a4 4 0 0 0-4-4H8a4 4 0 0 0-4 4v2" /><circle cx="12" cy="7" r="4" />
+                  </svg>
+                  <svg v-else xmlns="http://www.w3.org/2000/svg" width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                    <path d="M12 2a8 8 0 0 0-8 8c0 3.5 2 6 5 7.5V21h6v-3.5c3-1.5 5-4 5-7.5a8 8 0 0 0-8-8z" />
+                  </svg>
+                </span>
+                <span>{{ node.content_preview || '...' }}</span>
+                <span v-if="node.is_active" class="shrink-0 text-[10px] bg-amber-600/30 text-amber-400 px-1 rounded">active</span>
+              </button>
+            </div>
+          </div>
+        </template>
+
+        <!-- Context Files (landscape) -->
+        <template v-if="showContextFiles">
+          <div class="shrink-0 px-3 py-2 flex justify-end">
+            <button class="text-xs text-amber-400 hover:text-amber-300 transition-colors" @click="triggerFileUpload">
+              + Add file
+            </button>
+          </div>
+          <input ref="contextFileInputRef" type="file" multiple accept=".txt,.md,.json,.csv,.xml,.yaml,.yml,.log,.py,.js,.ts,.html,.css" class="hidden" @change="handleFileUpload" />
+          <div v-if="!contextFiles.length" class="px-3 py-3 text-sm text-stone-500">No files attached</div>
+          <div v-else class="flex-1 overflow-y-auto pb-2">
+            <div v-for="(file, index) in contextFiles" :key="index" class="flex items-center gap-2 px-3 py-1.5 hover:bg-stone-800/50">
+              <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" class="text-stone-500 shrink-0">
+                <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z" /><polyline points="14 2 14 8 20 8" />
+              </svg>
+              <span class="text-xs text-stone-300 truncate flex-1">{{ file.name }}</span>
+              <span class="text-[10px] text-stone-500">{{ Math.round(file.content.length / 1024) || '<1' }}KB</span>
+              <button class="text-stone-500 hover:text-red-400 transition-colors" @click="removeContextFile(index)">
+                <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                  <line x1="18" y1="6" x2="6" y2="18" /><line x1="6" y1="6" x2="18" y2="18" />
+                </svg>
+              </button>
+            </div>
+          </div>
+        </template>
+      </div>
+    </template>
   </div>
 </template>