fix(issues): close out Howard review on blocker 3 draft externalization (MUL-4475)

- edit composer (comment-card `useEditAttachmentState`): externalize
  pendingAttachments + suppressedAgentIds into the edit draft and re-hydrate
  them in startEdit, so uploading an attachment mid-edit → tab-switch remount →
  save keeps the attachment id (was dropped). Hook exported for testing.
- top-level + reply composers: persist attachments/suppressed only INTO an
  existing content draft (never fabricate a content-only empty draft), and
  always write the current value — incl. `[]` — so un-suppressing an agent no
  longer leaves a stale array that re-suppresses it on remount.
- issue-surface: import `getIssueSurfaceViewStore` from the public
  `@multica/core/issues/stores` barrel instead of the deep private path.

New regression coverage: edit attachment survives remount → save keeps id;
suppress → un-suppress persists `[]` and a remount stays un-suppressed;
toggling suppression with no content never creates an empty draft.

Verify: views typecheck clean; full views suite 1862 pass; eslint clean.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Co-authored-by: multica-agent <github@multica.ai>

packages/views/issues/components/comment-card.tsx

@@ -309,7 +309,7 @@ function TaskCommentRetryButton({
 // Shared edit-attachment state hook
 // ---------------------------------------------------------------------------
 
-function useEditAttachmentState(
+export function useEditAttachmentState(
   issueId: string,
   entry: TimelineEntry,
   onEdit: (commentId: string, content: string, attachmentIds: string[], suppressAgentIds?: string[]) => Promise<void>,
@@ -390,9 +390,28 @@ function useEditAttachmentState(
     clearDraft(draftKey);
   };
 
+  // Persist edit attachments + suppressed choices into the edit draft so a
+  // remount (desktop tab switch / virtualization) can restore them via
+  // startEdit — only into an existing content draft, always writing the
+  // current value (incl. `[]`). See CommentInput for the rationale.
+  useEffect(() => {
+    if (!editing) return;
+    if (useCommentDraftStore.getState().getDraft(draftKey) === undefined) return;
+    setDraft(draftKey, { attachments: pendingAttachments });
+  }, [editing, pendingAttachments, draftKey, setDraft]);
+
+  useEffect(() => {
+    if (!editing) return;
+    if (useCommentDraftStore.getState().getDraft(draftKey) === undefined) return;
+    setDraft(draftKey, { suppressedAgentIds: [...suppressedAgentIds] });
+  }, [editing, suppressedAgentIds, draftKey, setDraft]);
+
   const startEdit = () => {
     cancelledRef.current = false;
-    setContent(getDraft(draftKey)?.content ?? entry.content ?? "");
+    const draft = getDraft(draftKey);
+    setContent(draft?.content ?? entry.content ?? "");
+    setPendingAttachments(draft?.attachments ?? []);
+    setSuppressedAgentIds(new Set(draft?.suppressedAgentIds ?? []));
     setRetainedStandaloneIds(initialStandaloneAttachmentIds(entry));
     setEditing(true);
   };

packages/views/issues/components/comment-draft-persistence.test.tsx

@@ -0,0 +1,256 @@
+import {
+  forwardRef,
+  useImperativeHandle,
+  useRef,
+  act,
+  type Ref,
+} from "react";
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { fireEvent, render, screen, waitFor } from "@testing-library/react";
+import type { Attachment, TimelineEntry } from "@multica/core/types";
+import { useCommentDraftStore } from "@multica/core/issues/stores";
+import { CommentInput } from "./comment-input";
+import { useEditAttachmentState } from "./comment-card";
+
+// One controllable trigger agent so a suppression chip renders. Hoisted +
+// stable so the composer's "reconcile suppressed against visible agents" effect
+// runs once and toggling doesn't churn it.
+const mockAgents = vi.hoisted(() => [{ id: "ag-1", name: "Walt", source: "mention_agent" }]);
+
+vi.mock("../hooks/use-comment-trigger-preview", () => ({
+  useCommentTriggerPreview: () => ({ agents: mockAgents }),
+}));
+
+// Test double for the chip strip: one toggle button per agent.
+vi.mock("./comment-trigger-chips", () => ({
+  CommentTriggerChips: ({
+    agents,
+    suppressedAgentIds,
+    onToggle,
+  }: {
+    agents: { id: string; name: string }[];
+    suppressedAgentIds: Set<string>;
+    onToggle: (id: string) => void;
+  }) => (
+    <div>
+      {agents.map((a) => (
+        <button
+          key={a.id}
+          data-testid={`chip-${a.id}`}
+          aria-pressed={suppressedAgentIds.has(a.id)}
+          onClick={() => onToggle(a.id)}
+        >
+          {a.name}
+        </button>
+      ))}
+    </div>
+  ),
+}));
+
+vi.mock("@multica/core/api", () => ({ api: {} }));
+
+vi.mock("@multica/core/hooks/use-file-upload", () => ({
+  useFileUpload: () => ({ uploadWithToast: vi.fn() }),
+}));
+
+vi.mock("../../i18n", () => ({
+  useT: () => ({ t: () => "translated" }),
+  useTimeAgo: () => () => "now",
+}));
+
+vi.mock("../../editor", () => ({
+  useFileDropZone: () => ({
+    isDragOver: false,
+    dropZoneProps: { "data-testid": "drop-zone" },
+  }),
+  FileDropOverlay: () => null,
+  ContentEditor: forwardRef(function MockContentEditor(
+    {
+      defaultValue,
+      onUpdate,
+    }: {
+      defaultValue?: string;
+      onUpdate?: (markdown: string) => void;
+    },
+    ref: Ref<unknown>,
+  ) {
+    const valueRef = useRef(defaultValue ?? "");
+    useImperativeHandle(ref, () => ({
+      getMarkdown: () => valueRef.current,
+      clearContent: () => {
+        valueRef.current = "";
+      },
+      focus: () => {},
+      blur: () => {},
+      uploadFile: async () => {},
+      hasActiveUploads: () => false,
+    }));
+    return (
+      <textarea
+        data-testid="editor"
+        defaultValue={defaultValue}
+        onChange={(e) => {
+          valueRef.current = e.target.value;
+          onUpdate?.(e.target.value);
+        }}
+      />
+    );
+  }),
+}));
+
+function makeAttachment(id: string, url: string): Attachment {
+  return {
+    id,
+    workspace_id: "ws-1",
+    issue_id: "issue-1",
+    comment_id: null,
+    chat_session_id: null,
+    chat_message_id: null,
+    uploader_type: "member",
+    uploader_id: "u1",
+    filename: `${id}.png`,
+    url,
+    download_url: url,
+    markdown_url: url,
+    content_type: "image/png",
+    size_bytes: 1,
+    created_at: "2026-01-01T00:00:00Z",
+  };
+}
+
+beforeEach(() => {
+  localStorage.clear();
+  useCommentDraftStore.setState({ drafts: {} });
+});
+
+describe("comment composer suppression persistence", () => {
+  it("writes suppressedAgentIds:[] on un-suppress (no stale array, no empty draft) and a remount stays un-suppressed", async () => {
+    const view = render(<CommentInput issueId="issue-1" onSubmit={vi.fn().mockResolvedValue(true)} />);
+
+    // A content draft must exist for suppression to persist.
+    fireEvent.change(screen.getByTestId("editor"), { target: { value: "ping @walt" } });
+
+    fireEvent.click(screen.getByTestId("chip-ag-1")); // suppress
+    await waitFor(() =>
+      expect(
+        useCommentDraftStore.getState().getDraft("new:issue-1")?.suppressedAgentIds,
+      ).toEqual(["ag-1"]),
+    );
+
+    fireEvent.click(screen.getByTestId("chip-ag-1")); // un-suppress
+    await waitFor(() =>
+      expect(
+        useCommentDraftStore.getState().getDraft("new:issue-1")?.suppressedAgentIds,
+      ).toEqual([]),
+    );
+
+    // The content draft is preserved (not wiped, not turned into an empty draft).
+    expect(useCommentDraftStore.getState().getDraft("new:issue-1")?.content).toBe(
+      "ping @walt",
+    );
+
+    // Remount: the composer hydrates from the draft — the agent must NOT come
+    // back suppressed off a stale array.
+    view.unmount();
+    render(<CommentInput issueId="issue-1" onSubmit={vi.fn().mockResolvedValue(true)} />);
+    expect(screen.getByTestId("chip-ag-1")).toHaveAttribute("aria-pressed", "false");
+  });
+
+  it("never creates a content-only empty draft just from toggling suppression", () => {
+    render(<CommentInput issueId="issue-1" onSubmit={vi.fn().mockResolvedValue(true)} />);
+    // No content typed → toggling suppression must not persist anything.
+    fireEvent.click(screen.getByTestId("chip-ag-1"));
+    fireEvent.click(screen.getByTestId("chip-ag-1"));
+    expect(useCommentDraftStore.getState().getDraft("new:issue-1")).toBeUndefined();
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Edit composer: attachments survive a remount (blocker 3, edit path)
+// ---------------------------------------------------------------------------
+
+type EditApi = ReturnType<typeof useEditAttachmentState>;
+
+const MockEditEditor = forwardRef(function MockEditEditor(
+  { defaultValue }: { defaultValue?: string },
+  ref: Ref<unknown>,
+) {
+  const valueRef = useRef(defaultValue ?? "");
+  useImperativeHandle(ref, () => ({
+    getMarkdown: () => valueRef.current,
+    clearContent: () => {
+      valueRef.current = "";
+    },
+    focus: () => {},
+    blur: () => {},
+    uploadFile: async () => {},
+    hasActiveUploads: () => false,
+  }));
+  return <textarea data-testid="edit-editor" defaultValue={defaultValue} />;
+});
+
+function EditHarness({
+  entry,
+  onEdit,
+  capture,
+}: {
+  entry: TimelineEntry;
+  onEdit: (
+    commentId: string,
+    content: string,
+    attachmentIds: string[],
+    suppressAgentIds?: string[],
+  ) => Promise<void>;
+  capture: (api: EditApi) => void;
+}) {
+  const edit = useEditAttachmentState("issue-1", entry, onEdit);
+  capture(edit);
+  return edit.editing ? (
+    <MockEditEditor ref={edit.editorRef} defaultValue={edit.initialValue} />
+  ) : null;
+}
+
+describe("edit composer attachment persistence", () => {
+  it("re-hydrates an uploaded attachment on startEdit so save keeps its attachment id", async () => {
+    const att = makeAttachment("att-1", "http://x/att-1.png");
+    // A prior edit session uploaded att-1 (its URL is in the body) then the tab
+    // switched — the edit draft persisted content + attachments.
+    useCommentDraftStore.getState().setDraft("edit:issue-1:c-1", {
+      content: "edited body http://x/att-1.png",
+      attachments: [att],
+    });
+
+    const entry = {
+      id: "c-1",
+      content: "original body",
+      attachments: [],
+      parent_id: null,
+    } as unknown as TimelineEntry;
+    const onEdit = vi.fn().mockResolvedValue(undefined);
+
+    let api: EditApi | null = null;
+    render(
+      <EditHarness
+        entry={entry}
+        onEdit={onEdit}
+        capture={(a) => {
+          api = a;
+        }}
+      />,
+    );
+
+    act(() => {
+      api!.startEdit();
+    });
+    await act(async () => {
+      await api!.saveEdit();
+    });
+
+    expect(onEdit).toHaveBeenCalledWith(
+      "c-1",
+      "edited body http://x/att-1.png",
+      ["att-1"],
+      undefined,
+    );
+  });
+});

packages/views/issues/components/comment-input.tsx

@@ -93,17 +93,18 @@ function CommentInput({ issueId, onSubmit }: CommentInputProps) {
   }, [draftKey]);
 
   // Persist attachments + suppressed choices so the composer's full state
-  // survives an unmount (desktop tab switch / virtualization scroll-out).
+  // survives an unmount (desktop tab switch / virtualization scroll-out). Only
+  // write INTO an existing content draft — never create a content-less draft
+  // just to record these — and always write the current value (incl. `[]`) so
+  // clearing a suppression leaves no stale array to re-apply on remount.
   useEffect(() => {
-    if (pendingAttachments.length > 0) {
-      setDraft(draftKey, { attachments: pendingAttachments });
-    }
+    if (useCommentDraftStore.getState().getDraft(draftKey) === undefined) return;
+    setDraft(draftKey, { attachments: pendingAttachments });
   }, [pendingAttachments, draftKey, setDraft]);
 
   useEffect(() => {
-    if (suppressedAgentIds.size > 0) {
-      setDraft(draftKey, { suppressedAgentIds: [...suppressedAgentIds] });
-    }
+    if (useCommentDraftStore.getState().getDraft(draftKey) === undefined) return;
+    setDraft(draftKey, { suppressedAgentIds: [...suppressedAgentIds] });
   }, [suppressedAgentIds, draftKey, setDraft]);
 
   useEffect(() => {

packages/views/issues/components/reply-input.tsx

@@ -112,17 +112,20 @@ function ReplyInput({
     setSuppressedAgentIds(new Set(draft?.suppressedAgentIds ?? []));
   }, [draftKey, issueId, parentId]);
 
-  // Persist attachments + suppressed choices (only when a draftKey is present).
+  // Persist attachments + suppressed choices — only when a draftKey is present
+  // AND a content draft already exists (never create a content-less draft).
+  // Always write the current value (incl. `[]`) so clearing a suppression
+  // leaves no stale array to re-apply on remount.
   useEffect(() => {
-    if (draftKey && pendingAttachments.length > 0) {
-      setDraft(draftKey, { attachments: pendingAttachments });
-    }
+    if (!draftKey) return;
+    if (useCommentDraftStore.getState().getDraft(draftKey) === undefined) return;
+    setDraft(draftKey, { attachments: pendingAttachments });
   }, [draftKey, pendingAttachments, setDraft]);
 
   useEffect(() => {
-    if (draftKey && suppressedAgentIds.size > 0) {
-      setDraft(draftKey, { suppressedAgentIds: [...suppressedAgentIds] });
-    }
+    if (!draftKey) return;
+    if (useCommentDraftStore.getState().getDraft(draftKey) === undefined) return;
+    setDraft(draftKey, { suppressedAgentIds: [...suppressedAgentIds] });
   }, [draftKey, suppressedAgentIds, setDraft]);
 
   useEffect(() => {

packages/views/issues/surface/issue-surface.tsx

@@ -6,9 +6,11 @@ import { Button } from "@multica/ui/components/ui/button";
 import { Skeleton } from "@multica/ui/components/ui/skeleton";
 import { cn } from "@multica/ui/lib/utils";
 import { useWorkspaceId } from "@multica/core/hooks";
-import { ViewStoreProvider } from "@multica/core/issues/stores/view-store-context";
-import { useIssueViewStoreFactory } from "@multica/core/issues/stores";
-import { getIssueSurfaceViewStore } from "@multica/core/issues/stores/surface-view-store";
+import {
+  ViewStoreProvider,
+  useIssueViewStoreFactory,
+  getIssueSurfaceViewStore,
+} from "@multica/core/issues/stores";
 import { issueScopeKey } from "@multica/core/issues/surface/scope";
 import type { Issue } from "@multica/core/types";
 import { BoardView } from "../components/board-view";