refactor(comments): trim trigger preview copy and unify composer buttons

Two related cleanups to the issue comment/reply/edit composer:

- Drop the trigger-preview "context" copy added in #4147 (chip prefix
  `trigger_context_*` and per-context popover titles `trigger_preview_title_*`).
  The actual "align context" fix in #4147 was the backend/hook work; the copy
  was redundant decoration. Removes the `context` prop, the dead i18n keys
  across en/zh/ja/ko, and the corresponding test assertions; the popover title
  falls back to the original single `trigger_preview_title`.

- Edit-comment footer: lay the trigger chip on a single row with the action
  cluster (📎 Cancel Save) on the right, attachments on their own full-width
  row above. The 📎 now sits with the action buttons, matching the new-comment
  and reply composers.

- Unify composer buttons on shadcn `Button`: `FileUploadButton` renders a
  ghost icon button instead of a hand-rolled circle, and the reply submit
  button uses `Button` (icon-xs, ghost-when-empty / primary-when-typed) instead
  of a hand-rolled element. Sizes: 📎 and reply submit are both icon-xs (24px).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/ui/components/common/file-upload-button.tsx

@@ -3,6 +3,7 @@
 import { useRef } from "react";
 import { Paperclip } from "lucide-react";
 import { useTranslation } from "react-i18next";
+import { Button } from "@multica/ui/components/ui/button";
 import { cn } from "@multica/ui/lib/utils";
 
 interface FileUploadButtonProps {
@@ -33,24 +34,22 @@ function FileUploadButton({
   };
 
   const iconSize = size === "sm" ? "h-3.5 w-3.5" : "h-4 w-4";
-  const btnSize = size === "sm" ? "h-6 w-6" : "h-7 w-7";
+  const buttonSize = size === "sm" ? "icon-xs" : "icon-sm";
 
   return (
     <>
-      <button
+      <Button
         type="button"
+        variant="ghost"
+        size={buttonSize}
         onClick={() => inputRef.current?.click()}
         disabled={disabled}
         aria-label={attachLabel}
         title={attachLabel}
-        className={cn(
-          "inline-flex items-center justify-center rounded-full text-muted-foreground hover:bg-accent hover:text-foreground transition-colors disabled:opacity-50 disabled:pointer-events-none",
-          btnSize,
-          className,
-        )}
+        className={cn("text-muted-foreground", className)}
       >
         <Paperclip className={iconSize} />
-      </button>
+      </Button>
       <input
         ref={inputRef}
         type="file"

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

@@ -564,34 +564,33 @@ function CommentRow({
               attachments={edit.editorAttachments}
             />
           </div>
-          <div className="flex items-center justify-between mt-2">
-            <div className="flex min-w-0 flex-1 flex-col gap-1">
-              {edit.standaloneEditAttachments.length > 0 && (
-                <AttachmentList
-                  attachments={edit.standaloneEditAttachments}
-                  className="max-w-full"
-                  onRemove={(attachmentId) =>
-                    edit.setRetainedStandaloneIds((ids) => {
-                      const next = new Set(ids ?? []);
-                      next.delete(attachmentId);
-                      return next;
-                    })
-                  }
-                  />
-                )}
+          {edit.standaloneEditAttachments.length > 0 && (
+            <AttachmentList
+              attachments={edit.standaloneEditAttachments}
+              className="mt-2 max-w-full"
+              onRemove={(attachmentId) =>
+                edit.setRetainedStandaloneIds((ids) => {
+                  const next = new Set(ids ?? []);
+                  next.delete(attachmentId);
+                  return next;
+                })
+              }
+            />
+          )}
+          <div className="flex items-center justify-between gap-2 mt-2">
+            <div className="min-w-0 flex-1">
               <CommentTriggerChips
                 agents={edit.triggerPreview.agents}
                 suppressedAgentIds={edit.suppressedAgentIds}
                 onToggle={edit.toggleSuppressedAgent}
-                context="edit"
               />
+            </div>
+            <div className="flex shrink-0 items-center gap-2">
               <FileUploadButton
                 size="sm"
                 multiple
                 onSelect={(file) => edit.editorRef.current?.uploadFile(file)}
               />
-            </div>
-            <div className="flex items-center gap-2">
               <Button size="sm" variant="ghost" onClick={edit.cancelEdit}>{t(($) => $.comment.cancel_edit)}</Button>
               <Button size="sm" variant="outline" onClick={edit.saveEdit}>{t(($) => $.comment.save_action)}</Button>
             </div>
@@ -864,7 +863,6 @@ function CommentCardImpl({
                       agents={edit.triggerPreview.agents}
                       suppressedAgentIds={edit.suppressedAgentIds}
                       onToggle={edit.toggleSuppressedAgent}
-                      context="edit"
                     />
                     <FileUploadButton
                       size="sm"

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

@@ -155,7 +155,6 @@ function CommentInput({ issueId, onSubmit }: CommentInputProps) {
           agents={triggerPreview.agents}
           suppressedAgentIds={suppressedAgentIds}
           onToggle={toggleSuppressedAgent}
-          context="comment"
         />
       </div>
       <div className="absolute bottom-1 right-1.5 flex items-center gap-1">

packages/views/issues/components/comment-trigger-chips.test.tsx

@@ -45,7 +45,6 @@ describe("CommentTriggerChips", () => {
     );
 
     const chip = screen.getByRole("button");
-    expect(chip).toHaveTextContent("Comment");
     expect(chip).toHaveTextContent("Starts working when sent");
     expect(chip).toHaveAttribute("aria-pressed", "false");
 
@@ -53,19 +52,6 @@ describe("CommentTriggerChips", () => {
     expect(onToggle).toHaveBeenCalledWith("agent-1");
   });
 
-  it("labels reply trigger chips by composer context", () => {
-    renderWithI18n(
-      <CommentTriggerChips
-        agents={[walt]}
-        suppressedAgentIds={new Set()}
-        onToggle={vi.fn()}
-        context="reply"
-      />,
-    );
-
-    expect(screen.getByRole("button")).toHaveTextContent("Reply");
-  });
-
   it("dims a suppressed single agent into the skip state", () => {
     renderWithI18n(
       <CommentTriggerChips
@@ -123,13 +109,12 @@ describe("CommentTriggerChips", () => {
         agents={[walt, bob]}
         suppressedAgentIds={new Set()}
         onToggle={onToggle}
-        context="reply"
       />,
     );
 
     fireEvent.click(screen.getByRole("button"));
 
-    expect(screen.getByText("This reply will trigger")).toBeInTheDocument();
+    expect(screen.getByText("This comment will trigger")).toBeInTheDocument();
     const row = screen.getByRole("button", { name: /Bob/ });
     expect(row).toHaveTextContent("Bob");
     fireEvent.click(row);

packages/views/issues/components/comment-trigger-chips.tsx

@@ -29,11 +29,9 @@ interface CommentTriggerChipsProps {
   agents: CommentTriggerPreviewAgent[];
   suppressedAgentIds: Set<string>;
   onToggle: (agentId: string) => void;
-  context?: CommentTriggerContext;
 }
 
 type IssuesT = ReturnType<typeof useT<"issues">>["t"];
-type CommentTriggerContext = "comment" | "reply" | "edit";
 
 function sourceLabel(source: string, t: IssuesT): string {
   switch (source) {
@@ -61,28 +59,6 @@ function sourceReason(agent: CommentTriggerPreviewAgent, t: IssuesT): string {
   }
 }
 
-function triggerContextLabel(context: CommentTriggerContext, t: IssuesT): string {
-  switch (context) {
-    case "reply":
-      return t(($) => $.comment.trigger_context_reply);
-    case "edit":
-      return t(($) => $.comment.trigger_context_edit);
-    default:
-      return t(($) => $.comment.trigger_context_comment);
-  }
-}
-
-function triggerPreviewTitle(context: CommentTriggerContext, t: IssuesT): string {
-  switch (context) {
-    case "reply":
-      return t(($) => $.comment.trigger_preview_title_reply);
-    case "edit":
-      return t(($) => $.comment.trigger_preview_title_edit);
-    default:
-      return t(($) => $.comment.trigger_preview_title_comment);
-  }
-}
-
 // Presence is display metadata only — the trigger list itself is always the
 // backend preview. Online-ish agents start right away; offline ones queue.
 function useTriggerPresenceLine(agentId: string, t: IssuesT): string | null {
@@ -131,7 +107,6 @@ export function CommentTriggerChips({
   agents,
   suppressedAgentIds,
   onToggle,
-  context = "comment",
 }: CommentTriggerChipsProps) {
   const { t } = useT("issues");
 
@@ -146,7 +121,6 @@ export function CommentTriggerChips({
         agent={agent}
         suppressed={suppressedAgentIds.has(agent.id)}
         onToggle={onToggle}
-        context={context}
         t={t}
       />
     );
@@ -157,42 +131,20 @@ export function CommentTriggerChips({
       agents={agents}
       suppressedAgentIds={suppressedAgentIds}
       onToggle={onToggle}
-      context={context}
       t={t}
     />
   );
 }
 
-function TriggerContextPrefix({
-  context,
-  t,
-}: {
-  context: CommentTriggerContext;
-  t: IssuesT;
-}) {
-  return (
-    <>
-      <span className="shrink-0 text-[10px] font-semibold tracking-normal text-muted-foreground/80">
-        {triggerContextLabel(context, t)}
-      </span>
-      <span aria-hidden="true" className="shrink-0 text-muted-foreground/50">
-        ·
-      </span>
-    </>
-  );
-}
-
 function SingleTriggerChip({
   agent,
   suppressed,
   onToggle,
-  context,
   t,
 }: {
   agent: CommentTriggerPreviewAgent;
   suppressed: boolean;
   onToggle: (agentId: string) => void;
-  context: CommentTriggerContext;
   t: IssuesT;
 }) {
   const state = suppressed
@@ -220,7 +172,6 @@ function SingleTriggerChip({
               suppressed && "opacity-60",
             )}
           >
-            <TriggerContextPrefix context={context} t={t} />
             <TriggerAgentAvatar agent={agent} suppressed={suppressed} />
             <span className="truncate">{sentence}</span>
           </button>
@@ -237,13 +188,11 @@ function MultiTriggerChip({
   agents,
   suppressedAgentIds,
   onToggle,
-  context,
   t,
 }: {
   agents: CommentTriggerPreviewAgent[];
   suppressedAgentIds: Set<string>;
   onToggle: (agentId: string) => void;
-  context: CommentTriggerContext;
   t: IssuesT;
 }) {
   const [open, setOpen] = useState(false);
@@ -276,7 +225,6 @@ function MultiTriggerChip({
         />
       }
     >
-      <TriggerContextPrefix context={context} t={t} />
       <span className="inline-flex items-center">
         {heads.map((agent, i) => (
           <span
@@ -319,7 +267,7 @@ function MultiTriggerChip({
       </Tooltip>
       <PopoverContent align="start" className="w-64 p-2">
         <div className="px-1.5 pb-1 text-xs font-medium text-muted-foreground">
-          {triggerPreviewTitle(context, t)}
+          {t(($) => $.comment.trigger_preview_title)}
         </div>
         <div className="flex flex-col">
           {agents.map((agent) => {

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

@@ -4,6 +4,7 @@ import { useRef, useState, useCallback, useEffect } from "react";
 import { ArrowUp, Loader2 } from "lucide-react";
 import { ContentEditor, type ContentEditorRef, useFileDropZone, FileDropOverlay } from "../../editor";
 import { FileUploadButton } from "@multica/ui/components/common/file-upload-button";
+import { Button } from "@multica/ui/components/ui/button";
 import { ActorAvatar } from "../../common/actor-avatar";
 import { useFileUpload } from "@multica/core/hooks/use-file-upload";
 import { api } from "@multica/core/api";
@@ -189,7 +190,6 @@ function ReplyInput({
             agents={triggerPreview.agents}
             suppressedAgentIds={suppressedAgentIds}
             onToggle={toggleSuppressedAgent}
-            context="reply"
           />
         </div>
         <div className="absolute bottom-0 right-0 flex items-center gap-1">
@@ -198,23 +198,19 @@ function ReplyInput({
             multiple
             onSelect={(file) => editorRef.current?.uploadFile(file)}
           />
-          <button
+          <Button
             type="button"
+            variant={isEmpty ? "ghost" : "default"}
+            size="icon-xs"
             disabled={isEmpty || submitting}
             onClick={handleSubmit}
-            className={cn(
-              "inline-flex h-6 w-6 items-center justify-center rounded-full transition-colors disabled:pointer-events-none disabled:opacity-50",
-              isEmpty
-                ? "text-muted-foreground hover:bg-accent hover:text-foreground"
-                : "bg-primary text-primary-foreground hover:bg-primary/90",
-            )}
           >
             {submitting ? (
               <Loader2 className="h-3.5 w-3.5 animate-spin" />
             ) : (
               <ArrowUp className="h-3.5 w-3.5" />
             )}
-          </button>
+          </Button>
         </div>
         {isDragOver && <FileDropOverlay />}
       </div>

packages/views/locales/en/issues.json

@@ -279,9 +279,6 @@
     "trigger_source_mention_agent": "@mention",
     "trigger_source_mention_squad_leader": "squad",
     "trigger_source_unknown": "trigger",
-    "trigger_context_comment": "Comment",
-    "trigger_context_reply": "Reply",
-    "trigger_context_edit": "Edit",
     "trigger_skipped_label": "Skipped",
     "trigger_wont_trigger": "Won't be triggered",
     "trigger_none_will_trigger": "No agents will be triggered",
@@ -298,9 +295,6 @@
     "trigger_click_to_manage": "Click to manage who gets triggered this time.",
     "trigger_click_to_restore": "Won't be triggered this time. Click to restore.",
     "trigger_preview_title": "This comment will trigger",
-    "trigger_preview_title_comment": "This comment will trigger",
-    "trigger_preview_title_reply": "This reply will trigger",
-    "trigger_preview_title_edit": "This edit will trigger",
     "trigger_chip_aria": "{{name}} trigger: {{state}}",
     "resolve": {
       "resolve_thread_action": "Resolve thread",

packages/views/locales/ja/issues.json

@@ -271,9 +271,6 @@
     "trigger_source_mention_agent": "@メンション",
     "trigger_source_mention_squad_leader": "Squad",
     "trigger_source_unknown": "トリガー",
-    "trigger_context_comment": "コメント",
-    "trigger_context_reply": "返信",
-    "trigger_context_edit": "編集",
     "trigger_skipped_label": "スキップ",
     "trigger_wont_trigger": "トリガーされません",
     "trigger_none_will_trigger": "いずれもトリガーされません",
@@ -289,9 +286,6 @@
     "trigger_click_to_manage": "クリックして今回のトリガー対象を管理します。",
     "trigger_click_to_restore": "今回はトリガーされません。クリックで元に戻せます。",
     "trigger_preview_title": "このコメントでトリガーされる対象",
-    "trigger_preview_title_comment": "このコメントでトリガーされる対象",
-    "trigger_preview_title_reply": "この返信でトリガーされる対象",
-    "trigger_preview_title_edit": "この編集でトリガーされる対象",
     "trigger_chip_aria": "{{name}} のトリガー: {{state}}",
     "resolve": {
       "resolve_thread_action": "スレッドを解決",

packages/views/locales/ko/issues.json

@@ -279,9 +279,6 @@
     "trigger_source_mention_agent": "@멘션",
     "trigger_source_mention_squad_leader": "Squad",
     "trigger_source_unknown": "트리거",
-    "trigger_context_comment": "댓글",
-    "trigger_context_reply": "답글",
-    "trigger_context_edit": "편집",
     "trigger_skipped_label": "건너뜀",
     "trigger_wont_trigger": "트리거되지 않습니다",
     "trigger_none_will_trigger": "모두 트리거되지 않습니다",
@@ -297,9 +294,6 @@
     "trigger_click_to_manage": "클릭하여 이번 트리거 대상을 관리합니다.",
     "trigger_click_to_restore": "이번에는 트리거되지 않습니다. 클릭하면 복원됩니다.",
     "trigger_preview_title": "이 댓글로 트리거되는 대상",
-    "trigger_preview_title_comment": "이 댓글로 트리거되는 대상",
-    "trigger_preview_title_reply": "이 답글로 트리거되는 대상",
-    "trigger_preview_title_edit": "이 편집으로 트리거되는 대상",
     "trigger_chip_aria": "{{name}} 트리거: {{state}}",
     "resolve": {
       "resolve_thread_action": "스레드 해결",

packages/views/locales/zh-Hans/issues.json

@@ -276,9 +276,6 @@
     "trigger_source_mention_agent": "@mention",
     "trigger_source_mention_squad_leader": "squad",
     "trigger_source_unknown": "将触发",
-    "trigger_context_comment": "评论",
-    "trigger_context_reply": "回复",
-    "trigger_context_edit": "编辑",
     "trigger_skipped_label": "已跳过",
     "trigger_wont_trigger": "不会触发",
     "trigger_none_will_trigger": "全部不会触发",
@@ -294,9 +291,6 @@
     "trigger_click_to_manage": "点击管理本次触发对象。",
     "trigger_click_to_restore": "本次不触发，点击恢复。",
     "trigger_preview_title": "这条评论将触发",
-    "trigger_preview_title_comment": "这条评论将触发",
-    "trigger_preview_title_reply": "这条回复将触发",
-    "trigger_preview_title_edit": "本次编辑将触发",
     "trigger_chip_aria": "{{name}} 触发状态：{{state}}",
     "resolve": {
       "resolve_thread_action": "解决该讨论",