feat(cli): historique de messages navigable haut/bas dans la CLI custom + contrôles de cellule visibles pendant busy — persistance localStorage du transcript custom (CustomAgentChatView), layering des contrôles sous l'overlay busy (LayoutGrid), bump pointeur IdeaSDK (docs plugin minimal + hot reload) (QA verte: 65 tests CustomAgentChatView, 25 tests LayoutGrid chat/layering, npm build frontend OK)

frontend/src/features/agents/CustomAgentChatView.tsx

@@ -83,6 +83,7 @@ const chatConversationViewCache = new Map<string, CachedChatView>();
 const EMPTY_MODEL_RESPONSE_MESSAGE = "Le modèle n'a renvoyé aucune réponse.";
 const COMPOSER_RESIZE_STEP = 12;
 const FALLBACK_COMPOSER_HEIGHT = 64;
+const COMPOSER_HISTORY_LIMIT = 100;
 const MIN_REASONABLE_CHAT_TIMESTAMP_MS = Date.UTC(2020, 0, 1);
 const MAX_REASONABLE_CHAT_TIMESTAMP_MS = Date.UTC(2100, 0, 1);
 const MIN_REASONABLE_CHAT_TIMESTAMP_SECONDS = Math.floor(
@@ -416,6 +417,55 @@ function conversationCacheKey(
   return conversationId ? `${projectId}::${agentId}::${conversationId}` : null;
 }
 
+function composerHistoryStorageKey(
+  projectId: string,
+  agentId: string,
+  layoutId: string | undefined,
+  nodeId: string | undefined,
+): string {
+  return [
+    "idea.custom-chat-history",
+    projectId,
+    layoutId ?? "default",
+    nodeId ?? "agent",
+    agentId,
+  ].join(".");
+}
+
+function readComposerHistory(storageKey: string): string[] {
+  if (typeof window === "undefined") return [];
+  try {
+    const parsed: unknown = JSON.parse(window.localStorage.getItem(storageKey) ?? "[]");
+    if (!Array.isArray(parsed)) return [];
+    return parsed
+      .filter((entry): entry is string => typeof entry === "string")
+      .map((entry) => entry.trim())
+      .filter(Boolean)
+      .slice(-COMPOSER_HISTORY_LIMIT);
+  } catch {
+    return [];
+  }
+}
+
+function writeComposerHistory(storageKey: string, history: string[]): void {
+  if (typeof window === "undefined") return;
+  try {
+    window.localStorage.setItem(
+      storageKey,
+      JSON.stringify(history.slice(-COMPOSER_HISTORY_LIMIT)),
+    );
+  } catch {
+    /* local history only */
+  }
+}
+
+function appendComposerHistoryEntry(history: string[], text: string): string[] {
+  const entry = text.trim();
+  if (!entry) return history;
+  const withoutDuplicateTail = history.at(-1) === entry ? history.slice(0, -1) : history;
+  return [...withoutDuplicateTail, entry].slice(-COMPOSER_HISTORY_LIMIT);
+}
+
 function appendProgress(state: ChatViewState, progress: ReplyProgress): ChatViewState {
   let key = progressUpsertKey(progress, state.progressScope);
   let existingIndex = state.turns.findIndex(
@@ -953,6 +1003,7 @@ export function CustomAgentChatView({
   const lastPersistedDraftRef = useRef("");
   const draftRef = useRef("");
   draftRef.current = draft;
+  const draftBeforeHistoryNavigationRef = useRef("");
   const attachmentsRef = useRef<AttachmentDraft[]>([]);
   attachmentsRef.current = attachments;
   const imageTokenSeqRef = useRef(0);
@@ -1061,6 +1112,14 @@ export function CustomAgentChatView({
     () => conversationCacheKey(projectId, agentId, conversationId),
     [agentId, conversationId, projectId],
   );
+  const composerHistoryKey = useMemo(
+    () => composerHistoryStorageKey(projectId, agentId, layoutId, nodeId),
+    [agentId, layoutId, nodeId, projectId],
+  );
+  const [composerHistory, setComposerHistory] = useState<string[]>(() =>
+    readComposerHistory(composerHistoryKey),
+  );
+  const [, setComposerHistoryIndex] = useState<number | null>(null);
   const displayTurns = turns;
   const sessionLabel = structuredSessionLabel(profile.structuredAdapter);
   const [requesterDelegation, setRequesterDelegation] =
@@ -1127,9 +1186,82 @@ export function CustomAgentChatView({
 
   const editDraft = useCallback((text: string) => {
     if (!draftHydratedRef.current) draftEditedBeforeHydrationRef.current = true;
+    setComposerHistoryIndex(null);
+    draftBeforeHistoryNavigationRef.current = "";
     setDraft(text);
   }, []);
 
+  const recallComposerHistory = useCallback(
+    (direction: "previous" | "next") => {
+      if (composerHistory.length === 0) return;
+      setComposerHistoryIndex((current) => {
+        if (current === null && direction === "previous") {
+          draftBeforeHistoryNavigationRef.current = draftRef.current;
+        }
+        const nextIndex =
+          direction === "previous"
+            ? current === null
+              ? composerHistory.length - 1
+              : Math.max(0, current - 1)
+            : current === null
+              ? null
+              : current >= composerHistory.length - 1
+                ? null
+                : current + 1;
+        if (nextIndex === null) {
+          setDraft(draftBeforeHistoryNavigationRef.current);
+          draftBeforeHistoryNavigationRef.current = "";
+        } else {
+          setDraft(composerHistory[nextIndex] ?? "");
+        }
+        return nextIndex;
+      });
+    },
+    [composerHistory],
+  );
+
+  const handleComposerHistoryKeyDown = useCallback(
+    (event: KeyboardEvent<HTMLTextAreaElement>): boolean => {
+      if (
+        event.altKey ||
+        event.ctrlKey ||
+        event.metaKey ||
+        event.shiftKey ||
+        (event.key !== "ArrowUp" && event.key !== "ArrowDown")
+      ) {
+        return false;
+      }
+      const target = event.currentTarget;
+      if (
+        event.key === "ArrowUp" &&
+        target.value.slice(0, target.selectionStart).includes("\n")
+      ) {
+        return false;
+      }
+      if (
+        event.key === "ArrowDown" &&
+        target.value.slice(target.selectionEnd).includes("\n")
+      ) {
+        return false;
+      }
+      event.preventDefault();
+      recallComposerHistory(event.key === "ArrowUp" ? "previous" : "next");
+      return true;
+    },
+    [recallComposerHistory],
+  );
+
+  useEffect(() => {
+    const restored = readComposerHistory(composerHistoryKey);
+    setComposerHistory(restored);
+    setComposerHistoryIndex(null);
+    draftBeforeHistoryNavigationRef.current = "";
+  }, [composerHistoryKey]);
+
+  useEffect(() => {
+    writeComposerHistory(composerHistoryKey, composerHistory);
+  }, [composerHistory, composerHistoryKey]);
+
   useEffect(() => {
     void refreshRequesterDelegation();
   }, [refreshRequesterDelegation]);
@@ -1913,6 +2045,11 @@ export function CustomAgentChatView({
       markProjectCliInteractionFinished(projectId, interactionId);
       activeInteractionIdRef.current = null;
     };
+    if (text) {
+      setComposerHistory((prev) => appendComposerHistoryEntry(prev, text));
+      setComposerHistoryIndex(null);
+      draftBeforeHistoryNavigationRef.current = "";
+    }
     setDraft("");
     setAttachments([]);
     imageTokenSeqRef.current = 0;
@@ -2373,6 +2510,7 @@ export function CustomAgentChatView({
                     return;
                   }
                 }
+                if (handleComposerHistoryKeyDown(e)) return;
                 if (e.key === "Enter" && !e.shiftKey) {
                   e.preventDefault();
                   void send();