fix(routing): reject empty auto streams

components/chat/chat-history-sidebar.tsx

@@ -303,7 +303,7 @@ export function ChatHistorySidebar({
         </div>
       </div>
 
-      {filteredConversations.length > 0 && (
+      {selectedCount > 0 && filteredConversations.length > 0 && (
         <div className="flex shrink-0 items-center justify-between gap-2 border-b border-border/40 px-2 py-1.5">
           <button
             type="button"
@@ -372,24 +372,12 @@ export function ChatHistorySidebar({
                     tabIndex={0}
                     onClick={() => {
                       if (renamingId === conv.id) return;
-                      if (selectedCount > 0) {
-                        setSelectedIds((current) => {
-                          const next = new Set(current);
-                          if (next.has(conv.id)) {
-                            next.delete(conv.id);
-                          } else {
-                            next.add(conv.id);
-                          }
-                          return next;
-                        });
-                        return;
-                      }
                       onSelectConversation(conv.id);
                       if (isMobile) onMobileSheetOpenChange(false);
                     }}
                     onKeyDown={(e) => {
                       if (renamingId === conv.id) return;
-                      if (e.key === "Enter" || e.key === " ") {
+                      if (e.key === "Enter") {
                         e.preventDefault();
                         onSelectConversation(conv.id);
                         if (isMobile) onMobileSheetOpenChange(false);
@@ -406,9 +394,11 @@ export function ChatHistorySidebar({
                       aria-label={selected ? "Desmarcar conversa" : "Marcar conversa"}
                       onClick={(e) => toggleConversationSelected(e, conv.id)}
                       className={cn(
-                        "flex size-4 shrink-0 items-center justify-center rounded border border-border bg-background transition-opacity md:opacity-0 md:group-hover:opacity-100 md:group-focus-within:opacity-100",
-                        selected && "border-primary bg-primary text-primary-foreground opacity-100",
-                        selectedCount > 0 && "opacity-100",
+                        "shrink-0 items-center justify-center rounded border transition-all",
+                        selected || selectedCount > 0
+                          ? "flex size-4 border-border bg-background"
+                          : "hidden h-0 w-0 border-0 md:group-hover:flex md:group-hover:size-4 md:group-hover:border-border md:group-hover:bg-background",
+                        selected && "border-primary bg-primary text-primary-foreground",
                       )}
                     >
                       {selected ? <CheckIcon className="size-3" /> : null}

components/chat/chat-page.tsx

@@ -832,6 +832,7 @@ export function ChatPage() {
 
     try {
       let fullText = "";
+      let effectiveModelLabel = assistantModelLabel;
       if (browserProviderAdapter) {
         if (browserProviderAuthState !== "signed-in") {
           setBrowserProviderAuthState("loading");
@@ -883,6 +884,8 @@ export function ChatPage() {
       const { resolvedLabel: resolvedAssistantLabel, fallbackMeta: modelFallbackMeta } =
         resolveModelFallbackFromHeaders(response, assistantModelLabel, models, selectedProvider.label);
 
+      effectiveModelLabel = resolvedAssistantLabel ?? assistantModelLabel;
+
       setMessages((current) =>
         current.map((message) => {
           if (message.id !== assistantMessageId) {
@@ -974,7 +977,7 @@ export function ChatPage() {
           }
           const persisted = await persistMessagesForConversation(convId, [
             { parts: messageParts, role: "user" },
-            { content: fullText, parts: [{ text: fullText, type: "text" }], role: "assistant" },
+            { content: fullText, modelLabel: effectiveModelLabel, parts: [{ text: fullText, type: "text" }], role: "assistant" },
           ]);
           const [persistedUserMessage, persistedAssistantMessage] = persisted.messages;
           if (persistedUserMessage && persistedAssistantMessage) {
@@ -1588,7 +1591,7 @@ export function ChatPage() {
                   ) : null}
                   <div
                     className={cn(
-                      "rounded-2xl px-3.5 py-2.5 text-sm",
+                      "min-w-0 max-w-full overflow-hidden rounded-2xl px-3.5 py-2.5 text-sm",
                       message.role === "user"
                         ? "rounded-tr-md bg-primary text-primary-foreground"
                         : "rounded-tl-md bg-muted",
@@ -1621,7 +1624,7 @@ export function ChatPage() {
                       </div>
                     ) : message.role === "assistant" ? (
                       message.content ? (
-                        <div className="prose-sm">
+                        <div className="min-w-0 max-w-full overflow-hidden prose-sm">
                           <MarkdownRenderer content={message.content} />
                           {/* Blinking cursor during streaming */}
                           {pending && messageIndex === messages.length - 1 && !message.isError && (

components/markdown-renderer.tsx

@@ -61,7 +61,7 @@ export function MarkdownRenderer({ content }: { content: string }) {
   const normalised = normaliseMarkdown(content);
 
   return (
-    <div className="markdown-renderer">
+    <div className="markdown-renderer min-w-0 max-w-full overflow-hidden">
       <ReactMarkdown
         remarkPlugins={[remarkGfm, remarkMath]}
         rehypePlugins={[rehypeHighlight, rehypeKatex]}
@@ -85,6 +85,13 @@ export function MarkdownRenderer({ content }: { content: string }) {
               {children}
             </code>
           ),
+          table: ({ children, ...props }) => (
+            <div className="my-4 max-w-full overflow-x-auto rounded-lg border border-border">
+              <table className="min-w-max" {...props}>
+                {children}
+              </table>
+            </div>
+          ),
         }}
       >
         {normalised}

lib/chat-parts.ts

@@ -27,7 +27,12 @@ type TextPart = {
   type: "text";
 };
 
-export type ConversationMessagePart = AttachmentReferencePart | TextPart;
+type MetaPart = {
+  modelLabel: string;
+  type: "meta";
+};
+
+export type ConversationMessagePart = AttachmentReferencePart | MetaPart | TextPart;
 
 export type ConversationAttachmentDescriptor = {
   byteSize: number;
@@ -41,7 +46,7 @@ export type ConversationAttachmentDescriptor = {
 
 export type HydratedAttachmentPart = AttachmentReferencePart & ConversationAttachmentDescriptor;
 
-export type HydratedConversationMessagePart = HydratedAttachmentPart | TextPart;
+export type HydratedConversationMessagePart = HydratedAttachmentPart | MetaPart | TextPart;
 
 export function createMessageContentFallback(
   parts: readonly ConversationMessagePart[],
@@ -51,6 +56,9 @@ export function createMessageContentFallback(
       if (part.type === "text") {
         return part.text;
       }
+      if (part.type === "meta") {
+        return "";
+      }
 
       return `[${part.kind}] ${part.fileName}`;
     })

lib/chat-utils.ts

@@ -240,18 +240,33 @@ export function formatMessageTimestamp(createdAt: string): string {
   return `${day} ${time}`;
 }
 
+function extractMetaModelLabel(parts: HydratedConversationMessagePart[] | undefined): string | undefined {
+  if (!parts) return undefined
+  for (const part of parts) {
+    if (typeof part === 'object' && part !== null && 'type' in part && (part as Record<string, unknown>).type === 'meta') {
+      const label = (part as Record<string, unknown>).modelLabel
+      if (typeof label === 'string' && label.trim()) return label
+    }
+  }
+  return undefined
+}
+
 export function hydrateChatMessage(input: {
   message: PersistedConversationMessage;
   assistantModelLabel?: string;
 }): ChatMessage {
+  const metaLabel = input.message.role === 'assistant'
+    ? extractMetaModelLabel(input.message.parts)
+    : undefined
+
   return {
     content:
       input.message.role === "assistant"
         ? input.message.content
         : getUserMessageText({ content: input.message.content, parts: input.message.parts }),
     createdAt: input.message.createdAt,
     id: input.message.id,
-    modelLabel: input.message.role === "assistant" ? input.assistantModelLabel : undefined,
+    modelLabel: input.message.role === "assistant" ? (metaLabel ?? input.assistantModelLabel) : undefined,
     parts: input.message.role === "user" ? input.message.parts : undefined,
     role: input.message.role,
     toolCalls: [],
@@ -283,6 +298,7 @@ export function buildAttachmentLabel(attachment: { extractionStatus: AttachmentE
 
 export async function persistMessagesForConversation(conversationId: string, outgoingMessages: Array<{
   content?: string;
+  modelLabel?: string;
   parts?: ConversationMessagePart[];
   role: "assistant" | "user";
 }>) {

server/lib/conversation-attachments.ts

@@ -336,6 +336,13 @@ export function parseSingleMessagePart(rawPart: Record<string, unknown>): Conver
     };
   }
 
+  if (
+    rawPart.type === "meta" &&
+    typeof rawPart.modelLabel === "string"
+  ) {
+    return { modelLabel: rawPart.modelLabel, type: "meta" };
+  }
+
   return null;
 }
 
@@ -377,6 +384,11 @@ export function hydrateMessageParts(input: {
       return result;
     }
 
+    if (part.type === "meta") {
+      result.push(part);
+      return result;
+    }
+
     const attachment = input.attachmentsById.get(part.attachmentId);
     if (!attachment) {
       return result;

server/providers/cloudflareworkersai.ts

@@ -79,6 +79,9 @@ const app = createProviderApp({
           }
         | null
       const output = json?.result?.response || json?.result?.output_text || json?.result?.text || ''
+      if (!String(output).trim()) {
+        return upstreamErrorResponse('Cloudflare Workers AI', 502, 'Empty model response')
+      }
 
       return toVercelSingleTextResponse(String(output))
     } catch (error) {

server/routes/conversations.ts

@@ -31,6 +31,7 @@ app.use("*", async (c, next) => {
 
 type CreateMessageInput = {
   content?: string;
+  modelLabel?: string;
   parts?: ConversationMessagePart[];
   role: string;
 };
@@ -138,57 +139,58 @@ async function authorizeConversation(c: Context): Promise<AuthorizedConversation
 }
 
 async function persistMessages(conversationId: string, messages: CreateMessageInput[]) {
-  const createdMessages = await prisma.$transaction(async (tx) => {
-    const output: Array<{
-      content: string;
-      createdAt: Date;
-      id: string;
-      parts: Prisma.JsonValue | null;
-      role: string;
-    }> = [];
-
-    for (const message of messages) {
-      const parts = normalizeIncomingMessageParts(message.parts);
-      const fallbackContent = parts.length > 0
-        ? createMessageContentFallback(parts)
-        : (message.content ?? "").trim();
-
-      const created = await tx.message.create({
-        data: {
-          content: fallbackContent,
+  const createdMessages: Array<{
+    content: string;
+    createdAt: Date;
+    id: string;
+    parts: Prisma.JsonValue | null;
+    role: string;
+  }> = [];
+
+  for (const message of messages) {
+    const parts = normalizeIncomingMessageParts(message.parts);
+    const fallbackContent = parts.length > 0
+      ? createMessageContentFallback(parts)
+      : (message.content ?? "").trim();
+
+    const partsWithMeta = message.modelLabel
+      ? [...parts, { modelLabel: message.modelLabel, type: "meta" } as ConversationMessagePart]
+      : parts;
+
+    const created = await prisma.message.create({
+      data: {
+        content: fallbackContent,
+        conversationId,
+        role: message.role,
+        ...(partsWithMeta.length > 0 ? { parts: partsWithMeta as unknown as Prisma.InputJsonValue } : {}),
+      },
+      select: {
+        content: true,
+        createdAt: true,
+        id: true,
+        parts: true,
+        role: true,
+      },
+    });
+
+    const attachmentIds = parts
+      .filter((part) => part.type === "attachment")
+      .map((part) => part.attachmentId);
+
+    if (attachmentIds.length > 0) {
+      await prisma.conversationAttachment.updateMany({
+        data: { messageId: created.id },
+        where: {
           conversationId,
-          role: message.role,
-          ...(parts.length > 0 ? { parts: parts as unknown as Prisma.InputJsonValue } : {}),
-        },
-        select: {
-          content: true,
-          createdAt: true,
-          id: true,
-          parts: true,
-          role: true,
+          id: { in: attachmentIds },
         },
       });
-
-      const attachmentIds = parts
-        .filter((part) => part.type === "attachment")
-        .map((part) => part.attachmentId);
-
-      if (attachmentIds.length > 0) {
-        await tx.conversationAttachment.updateMany({
-          data: { messageId: created.id },
-          where: {
-            conversationId,
-            id: { in: attachmentIds },
-          },
-        });
-      }
-
-      output.push(created);
     }
 
-    await tx.conversation.update({ where: { id: conversationId }, data: {} });
-    return output;
-  });
+    createdMessages.push(created);
+  }
+
+  await prisma.conversation.update({ where: { id: conversationId }, data: {} });
 
   const attachments = await prisma.conversationAttachment.findMany({
     where: { conversationId },
@@ -462,10 +464,8 @@ app.delete("/:id/messages", async (c) => {
     return c.json({ deletedMessageIds: [] });
   }
 
-  await prisma.$transaction([
-    prisma.message.deleteMany({ where: { conversationId, id: { in: idsToDelete } } }),
-    prisma.conversation.update({ where: { id: conversationId }, data: {} }),
-  ]);
+  await prisma.message.deleteMany({ where: { conversationId, id: { in: idsToDelete } } });
+  await prisma.conversation.update({ where: { id: conversationId }, data: {} });
 
   return c.json({ deletedMessageIds: idsToDelete });
 });