fix(comments): unify rendering with RichTextEditor, fix mention/link colors

- Comment display: replace <Markdown> with <RichTextEditor editable={false}>
- Link color: primary → brand (blue)
- Mention color: brand → primary + semibold
- Add MentionHoverCard component with HoverCardTrigger render={<span />}
- Markdown.tsx: sync mention style to text-primary font-semibold

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web/components/common/mention-hover-card.tsx

@@ -0,0 +1,70 @@
+"use client";
+
+import type { ReactNode } from "react";
+import { Bot } from "lucide-react";
+import { HoverCard, HoverCardTrigger, HoverCardContent } from "@/components/ui/hover-card";
+import { ActorAvatar } from "@/components/common/actor-avatar";
+import { useWorkspaceStore } from "@/features/workspace";
+
+interface MentionHoverCardProps {
+  type: string;
+  id: string;
+  children: ReactNode;
+}
+
+function MentionHoverCard({ type, id, children }: MentionHoverCardProps) {
+  const members = useWorkspaceStore((s) => s.members);
+  const agents = useWorkspaceStore((s) => s.agents);
+
+  if (type === "member") {
+    const member = members.find((m) => m.user_id === id);
+    if (!member) return <>{children}</>;
+
+    return (
+      <HoverCard>
+        <HoverCardTrigger render={<span />} className="cursor-default">
+          {children}
+        </HoverCardTrigger>
+        <HoverCardContent align="start" className="w-auto min-w-48 max-w-72">
+          <div className="flex items-center gap-2.5">
+            <ActorAvatar actorType="member" actorId={id} size={32} />
+            <div className="min-w-0">
+              <p className="text-sm font-medium truncate">{member.name}</p>
+              <p className="text-xs text-muted-foreground truncate">{member.email}</p>
+            </div>
+          </div>
+        </HoverCardContent>
+      </HoverCard>
+    );
+  }
+
+  if (type === "agent") {
+    const agent = agents.find((a) => a.id === id);
+    if (!agent) return <>{children}</>;
+
+    return (
+      <HoverCard>
+        <HoverCardTrigger render={<span />} className="cursor-default">
+          {children}
+        </HoverCardTrigger>
+        <HoverCardContent align="start" className="w-auto min-w-48 max-w-72">
+          <div className="flex items-center gap-2.5">
+            <div className="flex h-8 w-8 shrink-0 items-center justify-center rounded-full bg-muted">
+              <Bot className="h-4 w-4 text-muted-foreground" />
+            </div>
+            <div className="min-w-0">
+              <p className="text-sm font-medium truncate">{agent.name}</p>
+              {agent.description && (
+                <p className="text-xs text-muted-foreground truncate">{agent.description}</p>
+              )}
+            </div>
+          </div>
+        </HoverCardContent>
+      </HoverCard>
+    );
+  }
+
+  return <>{children}</>;
+}
+
+export { MentionHoverCard };

apps/web/components/common/rich-text-editor.css

@@ -126,7 +126,7 @@
 
 /* Links */
 .rich-text-editor a {
-  color: var(--primary);
+  color: var(--brand);
   text-decoration: none;
 }
 
@@ -137,8 +137,8 @@
 
 /* Mentions */
 .rich-text-editor .mention {
-  color: var(--brand);
-  font-weight: 500;
+  color: var(--primary);
+  font-weight: 600;
   text-decoration: none;
   margin: 0 0.125rem;
 }

apps/web/components/markdown/Markdown.tsx

@@ -3,6 +3,7 @@ import ReactMarkdown, { type Components } from 'react-markdown'
 import rehypeRaw from 'rehype-raw'
 import remarkGfm from 'remark-gfm'
 import { cn } from '@/lib/utils'
+import { MentionHoverCard } from '@/components/common/mention-hover-card'
 import { CodeBlock, InlineCode } from './CodeBlock'
 import { preprocessLinks } from './linkify'
 
@@ -60,10 +61,15 @@ function createComponents(
     a: ({ href, children }) => {
       // Mention links: mention://member/id or mention://agent/id
       if (href?.startsWith('mention://')) {
+        const parts = href.replace('mention://', '').split('/')
+        const mentionType = parts[0] ?? 'member'
+        const mentionId = parts[1] ?? ''
         return (
-          <span className="text-brand font-medium mx-0.5">
-            {children}
-          </span>
+          <MentionHoverCard type={mentionType} id={mentionId}>
+            <span className="text-primary font-semibold mx-0.5">
+              {children}
+            </span>
+          </MentionHoverCard>
         )
       }
 

apps/web/features/issues/components/comment-card.tsx

@@ -15,7 +15,6 @@ import {
 import { Tooltip, TooltipTrigger, TooltipContent } from "@/components/ui/tooltip";
 import { ActorAvatar } from "@/components/common/actor-avatar";
 import { ReactionBar } from "@/components/common/reaction-bar";
-import { Markdown } from "@/components/markdown";
 import { useActorName } from "@/features/workspace";
 import { timeAgo } from "@/shared/utils";
 import { RichTextEditor, type RichTextEditorRef } from "@/components/common/rich-text-editor";
@@ -162,7 +161,7 @@ function CommentRow({
       ) : (
         <>
           <div className="mt-1.5 pl-8 text-sm leading-relaxed text-foreground/85">
-            <Markdown mode="minimal">{entry.content ?? ""}</Markdown>
+            <RichTextEditor defaultValue={entry.content ?? ""} editable={false} />
           </div>
           {!isTemp && (
             <ReactionBar