feat(frontend): UI archivos en cards (issue 0128)

- CardFilesPanel: tab Archivos con grid thumbs + boton subir/borrar
- CardForm: drag&drop en descripcion, inserta ref markdown en cursor
- CardChatPanel: drag&drop + boton paperclip, sube y envia ref como mensaje
- MessageBody: renderer markdown minimo (img inline + link chip)
- api.ts: listCardFiles, uploadCardFile (multipart), deleteCardFile
- types.ts: CardFile

frontend/src/components/CardEditPanel.tsx

@@ -1,8 +1,9 @@
-import { Box, Divider, Group, Tabs, Text } from "@mantine/core";
+import { Box, Divider, Group, Tabs } from "@mantine/core";
 import { IconLink, IconMessage, IconPaperclip } from "@tabler/icons-react";
 import { useState } from "react";
 import type { Card, CardMessage, User } from "../types";
 import { CardChatPanel } from "./CardChatPanel";
+import { CardFilesPanel } from "./CardFilesPanel";
 import { CardLinksPanel } from "./CardLinksPanel";
 import { CardForm, CardFormValues } from "./CardForm";
 
@@ -27,12 +28,15 @@ export function CardEditPanel({
 }: Props) {
   const [messages, setMessages] = useState<CardMessage[]>([]);
   const [liveCard, setLiveCard] = useState(card);
+  const [filesRefreshKey, setFilesRefreshKey] = useState(0);
 
   const wrappedSubmit = async (v: CardFormValues) => {
     setLiveCard((c) => ({ ...c, title: v.title, description: v.description, requester: v.requester, tags: v.tags, assignee_id: v.assignee_id }));
     await onSubmit(v);
   };
 
+  const bumpFiles = () => setFilesRefreshKey((k) => k + 1);
+
   return (
     <Group align="stretch" gap="md" wrap="nowrap" style={{ minHeight: 460 }}>
       <Box style={{ flex: "1 1 0", minWidth: 320 }}>
@@ -48,6 +52,8 @@ export function CardEditPanel({
             tags: liveCard.tags || [],
           }}
           submitLabel="Guardar"
+          cardId={liveCard.id}
+          onFileUploaded={bumpFiles}
           onSubmit={wrappedSubmit}
           onCancel={onCancel}
         />
@@ -58,7 +64,7 @@ export function CardEditPanel({
           <Tabs.List>
             <Tabs.Tab value="chat" leftSection={<IconMessage size={14} />}>Chat</Tabs.Tab>
             <Tabs.Tab value="links" leftSection={<IconLink size={14} />}>Enlaces</Tabs.Tab>
-            <Tabs.Tab value="files" leftSection={<IconPaperclip size={14} />} disabled>Archivos</Tabs.Tab>
+            <Tabs.Tab value="files" leftSection={<IconPaperclip size={14} />}>Archivos</Tabs.Tab>
           </Tabs.List>
           <Box pt="xs" style={{ flex: 1, minHeight: 0, display: "flex", flexDirection: "column" }}>
             <Tabs.Panel value="chat" style={{ flex: 1, minHeight: 0, display: "flex" }}>
@@ -68,6 +74,7 @@ export function CardEditPanel({
                   users={users}
                   currentUserId={currentUserId}
                   onMessagesChange={setMessages}
+                  onFileUploaded={bumpFiles}
                 />
               </Box>
             </Tabs.Panel>
@@ -75,9 +82,7 @@ export function CardEditPanel({
               <CardLinksPanel card={liveCard} messages={messages} />
             </Tabs.Panel>
             <Tabs.Panel value="files">
-              <Text size="sm" c="dimmed" ta="center" p="md">
-                Proximamente: adjuntos de archivos.
-              </Text>
+              <CardFilesPanel cardId={liveCard.id} refreshKey={filesRefreshKey} />
             </Tabs.Panel>
           </Box>
         </Tabs>