feat(26-02): create MobileChatView and wire ChatPanel for responsive layout

- MobileChatView: full-screen mobile chat using 100dvh, back button, safe-area input
- ChatPanel: conditionally renders MobileChatView on mobile via useMediaQuery
- ChatConversationList: wraps ScrollArea in PullToRefresh for mobile
- ChatInput: pb-[env(safe-area-inset-bottom)] padding + 44px Send button touch target
- ChatConversationItem: min-h-[48px] touch target per UI-SPEC

ui/src/components/ChatConversationItem.tsx

@@ -63,7 +63,7 @@ export function ChatConversationItem({
         if (e.key === "Enter" || e.key === " ") onSelect(conversation.id);
       }}
       className={cn(
-        "group flex flex-col gap-0.5 rounded px-2 py-1.5 cursor-pointer relative",
+        "group flex flex-col gap-0.5 rounded px-2 py-1.5 cursor-pointer relative min-h-[48px] justify-center",
         isActive ? "bg-accent/60" : "hover:bg-accent",
       )}
     >

ui/src/components/ChatConversationList.tsx

@@ -2,6 +2,8 @@ import { useEffect, useRef, useState } from "react";
 import { GitBranch, Plus, Search, X } from "lucide-react";
 import { useChatConversations } from "../hooks/useChatConversations";
 import { useChatPanel } from "../context/ChatPanelContext";
+import { useMediaQuery } from "../hooks/useMediaQuery";
+import { PullToRefresh } from "./PullToRefresh";
 import { ChatConversationItem } from "./ChatConversationItem";
 import { ScrollArea } from "@/components/ui/scroll-area";
 import { Skeleton } from "@/components/ui/skeleton";
@@ -40,7 +42,8 @@ export function ChatConversationList({ companyId }: ChatConversationListProps) {
     return () => window.removeEventListener("nexus:focus-chat-search", handler);
   }, []);
 
-  const { data, isLoading, hasNextPage, fetchNextPage, createMutation, updateMutation, deleteMutation } =
+  const isMobile = !useMediaQuery("(min-width: 768px)");
+  const { data, isLoading, hasNextPage, fetchNextPage, createMutation, updateMutation, deleteMutation, refetch } =
     useChatConversations(companyId, { search: debouncedSearch || undefined });
 
   const [deletingId, setDeletingId] = useState<string | null>(null);
@@ -153,45 +156,47 @@ export function ChatConversationList({ companyId }: ChatConversationListProps) {
         </div>
       </div>
 
-      <ScrollArea className="flex-1">
+      <PullToRefresh onRefresh={() => { void refetch(); }} enabled={isMobile}>
-        <div className="p-1 space-y-0.5">
+        <ScrollArea className="flex-1">
-          {isLoading ? (
+          <div className="p-1 space-y-0.5">
-            // Loading skeletons
+            {isLoading ? (
-            Array.from({ length: 5 }).map((_, i) => (
+              // Loading skeletons
-              <Skeleton key={i} className="h-10 w-full rounded" />
+              Array.from({ length: 5 }).map((_, i) => (
-            ))
+                <Skeleton key={i} className="h-10 w-full rounded" />
-          ) : sorted.length === 0 ? (
+              ))
-            <div className="p-4 text-center">
+            ) : sorted.length === 0 ? (
-              <p className="text-xs text-muted-foreground">No conversations yet</p>
+              <div className="p-4 text-center">
-              <p className="text-xs text-muted-foreground mt-1">
+                <p className="text-xs text-muted-foreground">No conversations yet</p>
-                Start a conversation to get help from your agents.
+                <p className="text-xs text-muted-foreground mt-1">
-              </p>
+                  Start a conversation to get help from your agents.
-            </div>
+                </p>
-          ) : (
-            sorted.map((conversation) => (
-              <div key={conversation.id} className="relative">
-                {conversation.parentConversationId && (
-                  <GitBranch className="absolute left-1 top-1/2 -translate-y-1/2 h-3 w-3 text-muted-foreground pointer-events-none z-10" />
-                )}
-                <div className={conversation.parentConversationId ? "pl-4" : undefined}>
-                  <ChatConversationItem
-                    conversation={conversation}
-                    isActive={activeConversationId === conversation.id}
-                    onSelect={setActiveConversationId}
-                    onRename={handleRename}
-                    onPin={handlePin}
-                    onArchive={handleArchive}
-                    onDelete={handleDeleteRequest}
-                  />
-                </div>
               </div>
-            ))
+            ) : (
-          )}
+              sorted.map((conversation) => (
+                <div key={conversation.id} className="relative">
+                  {conversation.parentConversationId && (
+                    <GitBranch className="absolute left-1 top-1/2 -translate-y-1/2 h-3 w-3 text-muted-foreground pointer-events-none z-10" />
+                  )}
+                  <div className={conversation.parentConversationId ? "pl-4" : undefined}>
+                    <ChatConversationItem
+                      conversation={conversation}
+                      isActive={activeConversationId === conversation.id}
+                      onSelect={setActiveConversationId}
+                      onRename={handleRename}
+                      onPin={handlePin}
+                      onArchive={handleArchive}
+                      onDelete={handleDeleteRequest}
+                    />
+                  </div>
+                </div>
+              ))
+            )}
 
-          {/* Infinite scroll sentinel */}
+            {/* Infinite scroll sentinel */}
-          <div ref={sentinelRef} className="h-1" />
+            <div ref={sentinelRef} className="h-1" />
-        </div>
+          </div>
-      </ScrollArea>
+        </ScrollArea>
+      </PullToRefresh>
 
       {/* Delete confirmation dialog */}
       <Dialog open={!!deletingId} onOpenChange={(open) => !open && setDeletingId(null)}>

ui/src/components/ChatInput.tsx

@@ -176,7 +176,7 @@ export function ChatInput({
           e.preventDefault();
           submit();
         }}
-        className="flex items-end gap-2"
+        className="flex items-end gap-2 pb-[env(safe-area-inset-bottom)]"
       >
         {/* Slash command takes priority over mention popover */}
         <div className="flex-1 relative">
@@ -255,7 +255,7 @@ export function ChatInput({
           size="icon"
           disabled={isEmpty || isSubmitting || disabled}
           aria-label="Send message"
-          className="shrink-0"
+          className="shrink-0 min-h-[44px] min-w-[44px]"
         >
           {isSubmitting ? (
             <Loader2 className="h-4 w-4 animate-spin" />

ui/src/components/ChatPanel.tsx

@@ -12,6 +12,7 @@ import { ChatStopButton } from "./ChatStopButton";
 import { ChatSearchDialog } from "./ChatSearchDialog";
 import { ChatBranchSelector } from "./ChatBranchSelector";
 import { ChatBookmarkList } from "./ChatBookmarkList";
+import { MobileChatView } from "./MobileChatView";
 import { Button } from "@/components/ui/button";
 import { chatApi } from "../api/chat";
 import { agentsApi } from "../api/agents";
@@ -20,10 +21,12 @@ import { useStreamingChat } from "../hooks/useStreamingChat";
 import { useBrainstormerDefault } from "../hooks/useBrainstormerDefault";
 import { useChatBookmarks, useToggleBookmark } from "../hooks/useChatBookmarks";
 import { useChatFileUpload } from "../hooks/useChatFileUpload";
+import { useMediaQuery } from "../hooks/useMediaQuery";
 import { resolveAgentFromContent } from "../lib/slash-commands";
 import type { AgentRole } from "@paperclipai/shared";
 
 export function ChatPanel() {
+  const isDesktop = useMediaQuery("(min-width: 768px)");
   const { chatOpen, setChatOpen, activeConversationId, setActiveConversationId, setScrollToMessageId } = useChatPanel();
   const { selectedCompanyId } = useCompany();
   const queryClient = useQueryClient();
@@ -246,6 +249,11 @@ export function ChatPanel() {
     startStream(lastUserContent, activeAgentId ?? undefined);
   };
 
+  // On mobile, render the full-screen MobileChatView instead of the desktop slide-in panel
+  if (!isDesktop) {
+    return <MobileChatView />;
+  }
+
   return (
     <aside
       aria-label="Chat"

ui/src/components/MobileChatView.tsx

@@ -0,0 +1,283 @@
+import { useCallback, useMemo, useState } from "react";
+import { ChevronLeft } from "lucide-react";
+import { useQueryClient } from "@tanstack/react-query";
+import { useChatPanel } from "../context/ChatPanelContext";
+import { useCompany } from "../context/CompanyContext";
+import { useToast } from "../context/ToastContext";
+import { useChatMessages } from "../hooks/useChatMessages";
+import { useStreamingChat } from "../hooks/useStreamingChat";
+import { useBrainstormerDefault } from "../hooks/useBrainstormerDefault";
+import { useChatBookmarks, useToggleBookmark } from "../hooks/useChatBookmarks";
+import { useChatFileUpload } from "../hooks/useChatFileUpload";
+import { useChatConversations } from "../hooks/useChatConversations";
+import { useQuery } from "@tanstack/react-query";
+import { chatApi } from "../api/chat";
+import { agentsApi } from "../api/agents";
+import { resolveAgentFromContent } from "../lib/slash-commands";
+import { ChatMessageList } from "./ChatMessageList";
+import { ChatInput } from "./ChatInput";
+import { ChatAgentSelector } from "./ChatAgentSelector";
+import { ChatConversationList } from "./ChatConversationList";
+import { ChatStopButton } from "./ChatStopButton";
+import { PullToRefresh } from "./PullToRefresh";
+import { Button } from "@/components/ui/button";
+import type { AgentRole } from "@paperclipai/shared";
+
+/**
+ * Full-screen mobile chat layout.
+ * - When no conversation is active: shows conversation list with pull-to-refresh
+ * - When a conversation is active: shows header + message list + sticky input
+ *
+ * Does NOT render any MobileNavBar — relies on the global MobileBottomNav in Layout.tsx.
+ */
+export function MobileChatView() {
+  const { activeConversationId, setActiveConversationId } = useChatPanel();
+  const { selectedCompanyId } = useCompany();
+  const queryClient = useQueryClient();
+  const { pushToast } = useToast();
+  const [isSending, setIsSending] = useState(false);
+  const [activeAgentId, setActiveAgentId] = useState<string | null>(null);
+
+  const { messages } = useChatMessages(activeConversationId);
+  const { streamingContent, isStreaming, startStream, stop } = useStreamingChat(activeConversationId);
+  const { pendingFiles, addFile, removeFile, clearCompleted, completedFileIds } = useChatFileUpload(activeConversationId);
+  const brainstormerDefaultId = useBrainstormerDefault();
+
+  // useChatConversations for refetch (pull-to-refresh)
+  const { refetch } = useChatConversations(selectedCompanyId);
+
+  // Auto-select brainstormer for new conversations
+  const effectiveBrainstormerId =
+    activeAgentId === null && brainstormerDefaultId !== null && !activeConversationId
+      ? brainstormerDefaultId
+      : activeAgentId;
+
+  // Load agents for routing and identity
+  const { data: agents = [], isLoading: agentsLoading } = useQuery({
+    queryKey: ["agents", selectedCompanyId],
+    queryFn: () => agentsApi.list(selectedCompanyId!),
+    enabled: !!selectedCompanyId,
+  });
+
+  // Agent map for identity bars
+  const agentMap = useMemo(() => {
+    const map = new Map<string, { name: string; icon: string | null; role: AgentRole | null }>();
+    for (const a of agents) {
+      map.set(a.id, { name: a.name, icon: a.icon, role: (a.role as AgentRole) ?? null });
+    }
+    return map;
+  }, [agents]);
+
+  const streamingAgent = effectiveBrainstormerId
+    ? agentMap.get(effectiveBrainstormerId)
+    : undefined;
+
+  // Bookmark state
+  const { data: bookmarkData } = useChatBookmarks(selectedCompanyId, activeConversationId ?? undefined);
+  const { toggleBookmark } = useToggleBookmark();
+  const bookmarkedMessageIds = useMemo(() => {
+    const ids = new Set<string>();
+    for (const b of bookmarkData?.items ?? []) ids.add(b.message.id);
+    return ids;
+  }, [bookmarkData]);
+
+  // Get active conversation title for header
+  const { data: conversationsData } = useQuery({
+    queryKey: ["chat", "conversations", selectedCompanyId, ""],
+    queryFn: () => chatApi.listConversations(selectedCompanyId!, {}),
+    enabled: !!selectedCompanyId && !!activeConversationId,
+  });
+  const activeConversation = conversationsData?.items.find((c) => c.id === activeConversationId);
+  const conversationTitle = activeConversation?.title ?? "New Conversation";
+
+  const handleHandoff = useCallback(
+    async (spec: { what: string; why: string; constraints: string; success: string }) => {
+      if (!activeConversationId) return;
+      try {
+        await chatApi.handoffSpec(activeConversationId, spec, "pm");
+        queryClient.invalidateQueries({ queryKey: ["chat", "messages", activeConversationId] });
+      } catch {
+        pushToast({ title: "Could not send to PM. Try again.", tone: "error" });
+      }
+    },
+    [activeConversationId, queryClient, pushToast],
+  );
+
+  const handleSend = async (content: string) => {
+    if (!selectedCompanyId) return;
+    const resolvedAgentId = resolveAgentFromContent(content, agents, effectiveBrainstormerId);
+    const fileIdsToAttach = [...completedFileIds];
+
+    setIsSending(true);
+    try {
+      if (!activeConversationId) {
+        const newConvo = await chatApi.createConversation(selectedCompanyId, {
+          agentId: resolvedAgentId ?? undefined,
+        });
+        setActiveConversationId(newConvo.id);
+        const message = await chatApi.postMessage(newConvo.id, { role: "user", content });
+        if (fileIdsToAttach.length > 0) {
+          await chatApi.attachFilesToMessage(fileIdsToAttach, message.id);
+          clearCompleted();
+          queryClient.invalidateQueries({ queryKey: ["chat", "messages", newConvo.id] });
+        }
+        queryClient.invalidateQueries({ queryKey: ["chat"] });
+      } else {
+        const message = await chatApi.postMessage(activeConversationId, { role: "user", content });
+        if (fileIdsToAttach.length > 0) {
+          await chatApi.attachFilesToMessage(fileIdsToAttach, message.id);
+          clearCompleted();
+        }
+        queryClient.invalidateQueries({ queryKey: ["chat", "messages", activeConversationId] });
+        startStream(content, resolvedAgentId ?? undefined);
+      }
+    } finally {
+      setIsSending(false);
+    }
+  };
+
+  const handleEdit = async (messageId: string, newContent: string) => {
+    if (!activeConversationId) return;
+    const editedIdx = messages.findIndex((m) => m.id === messageId);
+    const hasSubsequentMessages = editedIdx >= 0 && editedIdx < messages.length - 1;
+
+    if (hasSubsequentMessages) {
+      try {
+        const newConv = await chatApi.branchConversation(activeConversationId, messageId);
+        setActiveConversationId(newConv.id);
+        queryClient.invalidateQueries({ queryKey: ["chat", "branches"] });
+        queryClient.invalidateQueries({ queryKey: ["chat"] });
+        await chatApi.editMessage(newConv.id, messageId, newContent);
+        await chatApi.truncateMessagesAfter(newConv.id, messageId);
+        queryClient.invalidateQueries({ queryKey: ["chat", "messages", newConv.id] });
+        startStream(newContent, effectiveBrainstormerId ?? undefined);
+      } catch {
+        pushToast({ title: "Could not create branch. Try again.", tone: "error" });
+      }
+    } else {
+      await chatApi.editMessage(activeConversationId, messageId, newContent);
+      await chatApi.truncateMessagesAfter(activeConversationId, messageId);
+      queryClient.invalidateQueries({ queryKey: ["chat", "messages", activeConversationId] });
+      startStream(newContent, effectiveBrainstormerId ?? undefined);
+    }
+  };
+
+  const handleRetry = async (assistantMessageId: string) => {
+    if (!activeConversationId || !messages) return;
+    const assistantIdx = messages.findIndex((m) => m.id === assistantMessageId);
+    if (assistantIdx < 0) return;
+
+    let lastUserContent = "";
+    let userMessageId = "";
+    for (let i = assistantIdx - 1; i >= 0; i--) {
+      if (messages[i]!.role === "user") {
+        lastUserContent = messages[i]!.content;
+        userMessageId = messages[i]!.id;
+        break;
+      }
+    }
+    if (!lastUserContent || !userMessageId) return;
+
+    await chatApi.truncateMessagesAfter(activeConversationId, userMessageId);
+    queryClient.invalidateQueries({ queryKey: ["chat", "messages", activeConversationId] });
+    startStream(lastUserContent, effectiveBrainstormerId ?? undefined);
+  };
+
+  const handleBookmark = useCallback(
+    (messageId: string) => {
+      if (!activeConversationId) return;
+      toggleBookmark({ conversationId: activeConversationId, messageId });
+    },
+    [activeConversationId, toggleBookmark],
+  );
+
+  const handleRefresh = async () => {
+    await refetch();
+  };
+
+  // Conversation list view (no active conversation)
+  if (!activeConversationId) {
+    return (
+      <div className="fixed inset-0 z-40 flex h-[100dvh] flex-col bg-background">
+        {/* pb-16 accounts for the existing MobileBottomNav (h-16) at the bottom of Layout */}
+        <div className="flex-1 overflow-hidden pb-16">
+          {selectedCompanyId ? (
+            <PullToRefresh onRefresh={handleRefresh} enabled={true}>
+              <ChatConversationList companyId={selectedCompanyId} />
+            </PullToRefresh>
+          ) : (
+            <div className="flex h-full items-center justify-center p-4">
+              <p className="text-sm text-muted-foreground">No workspace selected</p>
+            </div>
+          )}
+        </div>
+      </div>
+    );
+  }
+
+  // Active conversation view
+  return (
+    <div className="fixed inset-0 z-40 flex h-[100dvh] flex-col bg-background">
+      {/* Header: 48px tall */}
+      <div className="flex h-12 flex-shrink-0 items-center gap-2 border-b border-border px-3">
+        <Button
+          variant="ghost"
+          size="icon"
+          className="h-8 w-8"
+          onClick={() => setActiveConversationId(null)}
+          aria-label="Back to conversations"
+        >
+          <ChevronLeft className="h-5 w-5" />
+        </Button>
+        <span className="flex-1 truncate text-sm font-medium">{conversationTitle}</span>
+        {selectedCompanyId && (
+          <ChatAgentSelector
+            companyId={selectedCompanyId}
+            conversationId={activeConversationId}
+            agentId={effectiveBrainstormerId}
+            onAgentChange={setActiveAgentId}
+          />
+        )}
+      </div>
+
+      {/* Message list: fills remaining space */}
+      <div className="flex-1 overflow-hidden">
+        <ChatMessageList
+          conversationId={activeConversationId}
+          streamingContent={streamingContent}
+          isStreaming={isStreaming}
+          streamingAgentName={streamingAgent?.name ?? null}
+          streamingAgentIcon={streamingAgent?.icon ?? null}
+          streamingAgentRole={streamingAgent?.role ?? null}
+          onEdit={handleEdit}
+          onRetry={handleRetry}
+          onHandoff={handleHandoff}
+          agentMap={agentMap}
+          onBookmark={handleBookmark}
+          bookmarkedMessageIds={bookmarkedMessageIds}
+        />
+      </div>
+
+      {/* Stop button (shown during streaming) */}
+      {isStreaming && <ChatStopButton onStop={stop} />}
+
+      {/* Sticky input bar with safe area inset */}
+      <div className="sticky bottom-0 border-t border-border bg-background pb-[env(safe-area-inset-bottom)]">
+        <div className="px-3 py-2">
+          <ChatInput
+            onSend={handleSend}
+            isSubmitting={isSending}
+            disabled={isStreaming}
+            placeholder={isStreaming ? "Waiting for response..." : "Message your agent..."}
+            agents={agents}
+            agentsLoading={agentsLoading}
+            pendingFiles={pendingFiles}
+            onRemoveFile={removeFile}
+            onFilesPicked={(files) => files.forEach(addFile)}
+            enableVoiceInput={true}
+          />
+        </div>
+      </div>
+    </div>
+  );
+}