feat(cli): références d'attachments [file n]/[image n] dans le transcript + zone chat redimensionnable — #188 (QA verte)

- Attachments: projection canonique ChatPromptAttachmentDto (référence [file n]/[image n] par compteur de type, ordre d'import) insérée dans le prompt modèle et transportée par ReplyChunk::UserPrompt (attachmentRefs) ; rendu compact côté CustomAgentChatView.
- Resize: la zone chat (LeafView/LayoutGrid) est redimensionnable, taille actuelle conservée par défaut, préférence locale persistée.
- Tests: commands (projection des refs), dto_chat, chat_bridge, CustomAgentChatView, LayoutGrid.chat.

frontend/src/features/agents/CustomAgentChatView.tsx

@@ -17,6 +17,7 @@ import {
 
 import type {
   AgentProfile,
+  ChatPromptAttachment,
   GatewayError,
   ReplyChunk,
   ReplyProgress,
@@ -50,7 +51,7 @@ export interface CustomAgentChatViewProps {
 }
 
 type ChatTurn =
-  | { role: "user"; text: string; attachments?: string[] }
+  | { role: "user"; text: string; attachments?: ChatPromptAttachment[] }
   | { role: "agent"; text: string; pending?: boolean }
   | { role: "tool"; label: string }
   | { role: "progress"; progress: ReplyProgress; settled?: boolean }
@@ -158,10 +159,62 @@ function attachmentLabels(value: unknown): string[] {
     : [];
 }
 
+function isImageFilename(filename: string): boolean {
+  return /\.(apng|avif|gif|jpe?g|png|svg|webp)$/i.test(filename.trim());
+}
+
+function fallbackAttachmentRefs(labels: string[]): ChatPromptAttachment[] {
+  let imageCount = 0;
+  let fileCount = 0;
+  return labels.map((filename) => {
+    const image = isImageFilename(filename);
+    const reference = image ? `[image ${++imageCount}]` : `[file ${++fileCount}]`;
+    return { reference, filename };
+  });
+}
+
+function attachmentRefs(value: unknown, labels: string[] = []): ChatPromptAttachment[] {
+  if (Array.isArray(value)) {
+    const refs = value
+      .map((item): ChatPromptAttachment | null => {
+        if (!item || typeof item !== "object") return null;
+        const record = item as Record<string, unknown>;
+        const reference = optionalString(record.reference);
+        const filename = optionalString(record.filename);
+        if (!reference || !filename) return null;
+        return {
+          reference,
+          filename,
+          mime: optionalString(record.mime),
+          sizeBytes: typeof record.sizeBytes === "number" ? record.sizeBytes : undefined,
+          readablePath: optionalString(record.readablePath),
+        };
+      })
+      .filter((item): item is ChatPromptAttachment => Boolean(item));
+    if (refs.length > 0) return refs;
+  }
+  return fallbackAttachmentRefs(labels);
+}
+
+function attachmentRefsFromDrafts(attachments: AttachmentDraft[]): ChatPromptAttachment[] {
+  let imageCount = 0;
+  let fileCount = 0;
+  return attachments.map((attachment) => {
+    const mime = attachment.input.mime ?? "";
+    const image = mime.startsWith("image/") || (!mime && isImageFilename(attachment.label));
+    const reference = image ? `[image ${++imageCount}]` : `[file ${++fileCount}]`;
+    return {
+      reference,
+      filename: attachment.label,
+      mime: attachment.input.mime,
+    };
+  });
+}
+
 function appendUserPrompt(
   turns: ChatTurn[],
   text: string,
-  attachments: string[] = [],
+  attachments: ChatPromptAttachment[] = [],
 ): ChatTurn[] {
   const last = turns[turns.length - 1];
   if (
@@ -589,7 +642,7 @@ function foldChunk(state: ChatViewState, raw: unknown): ChatViewState {
         turns: appendUserPrompt(
           turns,
           String(raw.text ?? raw.prompt ?? ""),
-          attachmentLabels(raw.attachments),
+          attachmentRefs(raw.attachmentRefs, attachmentLabels(raw.attachments)),
         ),
         entityProgressMap: state.entityProgressMap,
       };
@@ -1359,7 +1412,7 @@ export function CustomAgentChatView({
     }
     const outgoingAttachments = attachments;
     const attachmentInputs = outgoingAttachments.map((item) => item.input);
-    const attachmentLabels = outgoingAttachments.map((item) => item.label);
+    const attachmentRefs = attachmentRefsFromDrafts(outgoingAttachments);
     const displayText = text || "Pièce jointe";
     const interactionId = `${agentId}:${++interactionSeqRef.current}`;
     activeInteractionIdRef.current = interactionId;
@@ -1380,7 +1433,7 @@ export function CustomAgentChatView({
         {
           role: "user",
           text: displayText,
-          ...(attachmentLabels.length > 0 ? { attachments: attachmentLabels } : {}),
+          ...(attachmentRefs.length > 0 ? { attachments: attachmentRefs } : {}),
         },
       ],
       entityProgressMap: prev.entityProgressMap,
@@ -1855,8 +1908,8 @@ function ChatBubble({
         {user && turn.attachments && turn.attachments.length > 0 && (
           <div className="mt-1 flex flex-col gap-0.5 text-xs text-muted">
             {turn.attachments.map((attachment) => (
-              <p key={attachment} className="truncate">
-                Fichier: {attachment}
+              <p key={`${attachment.reference}-${attachment.filename}`} className="truncate">
+                {attachment.reference} {attachment.filename}
               </p>
             ))}
           </div>