feat: @mention autocomplete in chat input + mention highlighting

src/components/ChatPanel.tsx

@@ -2,6 +2,7 @@ import { useCallback, useEffect, useRef, useState } from "react";
 import type { Message } from "@/lib/api";
 import { getMessages, sendMessage } from "@/lib/api";
 import { wsClient } from "@/lib/ws";
+import MentionInput from "./MentionInput";
 
 const PAGE_SIZE = 30;
 
@@ -13,9 +14,10 @@ const AUTHOR_ICON: Record<string, string> = {
 
 interface Props {
   chatId: string;
+  projectSlug?: string;
 }
 
-export default function ChatPanel({ chatId }: Props) {
+export default function ChatPanel({ chatId, projectSlug }: Props) {
   const [messages, setMessages] = useState<Message[]>([]);
   const [input, setInput] = useState("");
   const [sending, setSending] = useState(false);
@@ -114,6 +116,17 @@ export default function ChatPanel({ chatId }: Props) {
     }
   };
 
+  const renderContent = (text: string) => {
+    const parts = text.split(/(@\w+)/g);
+    return parts.map((part, i) =>
+      /^@\w+$/.test(part) ? (
+        <span key={i} className="text-[var(--accent)] font-medium">{part}</span>
+      ) : (
+        <span key={i}>{part}</span>
+      )
+    );
+  };
+
   const renderMessage = (msg: Message) => {
     const bgStyle =
       msg.author_type === "system"
@@ -129,7 +142,7 @@ export default function ChatPanel({ chatId }: Props) {
           <span>·</span>
           <span>{new Date(msg.created_at).toLocaleString("ru-RU", { hour: "2-digit", minute: "2-digit" })}</span>
         </div>
-        <div className="ml-5 whitespace-pre-wrap">{msg.content}</div>
+        <div className="ml-5 whitespace-pre-wrap">{renderContent(msg.content)}</div>
       </div>
     );
   };
@@ -153,18 +166,19 @@ export default function ChatPanel({ chatId }: Props) {
         )}
         <div ref={bottomRef} />
       </div>
-      <div className="px-6 py-3 border-t border-[var(--border)] flex gap-2">
-        <input
+      <div className="px-6 py-3 border-t border-[var(--border)] flex gap-2 items-end">
+        <MentionInput
+          projectSlug={projectSlug || ""}
           value={input}
-          onChange={(e) => setInput(e.target.value)}
-          onKeyDown={(e) => e.key === "Enter" && handleSend()}
-          placeholder="Сообщение..."
-          className="flex-1 bg-[var(--bg)] border border-[var(--border)] rounded-lg px-4 py-2 text-sm outline-none focus:border-[var(--accent)]"
+          onChange={setInput}
+          onSubmit={handleSend}
+          placeholder="Сообщение... (@mention)"
+          disabled={sending}
         />
         <button
           onClick={handleSend}
           disabled={sending}
-          className="px-4 py-2 bg-[var(--accent)] text-white rounded-lg text-sm hover:opacity-90 disabled:opacity-50"
+          className="px-4 py-2 bg-[var(--accent)] text-white rounded-lg text-sm hover:opacity-90 disabled:opacity-50 shrink-0"
         >
           ↵
         </button>

src/components/MentionInput.tsx

@@ -0,0 +1,155 @@
+import { useCallback, useEffect, useRef, useState } from "react";
+import type { ProjectMember } from "@/lib/api";
+import { getProjectMembers } from "@/lib/api";
+
+interface Props {
+  projectSlug: string;
+  value: string;
+  onChange: (value: string) => void;
+  onSubmit: () => void;
+  placeholder?: string;
+  disabled?: boolean;
+}
+
+export default function MentionInput({ projectSlug, value, onChange, onSubmit, placeholder, disabled }: Props) {
+  const [members, setMembers] = useState<ProjectMember[]>([]);
+  const [showDropdown, setShowDropdown] = useState(false);
+  const [filter, setFilter] = useState("");
+  const [selectedIdx, setSelectedIdx] = useState(0);
+  const [mentionStart, setMentionStart] = useState(-1);
+  const inputRef = useRef<HTMLTextAreaElement>(null);
+  const dropdownRef = useRef<HTMLDivElement>(null);
+
+  // Load members once
+  useEffect(() => {
+    if (!projectSlug) return;
+    getProjectMembers(projectSlug).then(setMembers).catch(() => {});
+  }, [projectSlug]);
+
+  const filtered = members.filter((m) =>
+    m.name.toLowerCase().includes(filter.toLowerCase()) ||
+    m.slug.toLowerCase().includes(filter.toLowerCase())
+  );
+
+  const insertMention = useCallback((member: ProjectMember) => {
+    if (mentionStart < 0) return;
+    const before = value.slice(0, mentionStart);
+    const after = value.slice(inputRef.current?.selectionStart ?? value.length);
+    const newValue = `${before}@${member.slug} ${after}`;
+    onChange(newValue);
+    setShowDropdown(false);
+    setMentionStart(-1);
+    // Focus and set cursor after mention
+    requestAnimationFrame(() => {
+      const el = inputRef.current;
+      if (el) {
+        const pos = before.length + member.slug.length + 2; // @slug + space
+        el.focus();
+        el.setSelectionRange(pos, pos);
+      }
+    });
+  }, [value, mentionStart, onChange]);
+
+  const handleChange = (e: React.ChangeEvent<HTMLTextAreaElement>) => {
+    const newVal = e.target.value;
+    onChange(newVal);
+
+    const cursorPos = e.target.selectionStart;
+    // Find @ before cursor
+    const textBeforeCursor = newVal.slice(0, cursorPos);
+    const lastAt = textBeforeCursor.lastIndexOf("@");
+
+    if (lastAt >= 0) {
+      // Check: @ must be at start or after whitespace
+      const charBefore = lastAt > 0 ? textBeforeCursor[lastAt - 1] : " ";
+      if (/\s/.test(charBefore) || lastAt === 0) {
+        const query = textBeforeCursor.slice(lastAt + 1);
+        // No spaces in mention query
+        if (!/\s/.test(query)) {
+          setMentionStart(lastAt);
+          setFilter(query);
+          setShowDropdown(true);
+          setSelectedIdx(0);
+          return;
+        }
+      }
+    }
+    setShowDropdown(false);
+  };
+
+  const handleKeyDown = (e: React.KeyboardEvent<HTMLTextAreaElement>) => {
+    if (showDropdown && filtered.length > 0) {
+      if (e.key === "ArrowDown") {
+        e.preventDefault();
+        setSelectedIdx((i) => (i + 1) % filtered.length);
+        return;
+      }
+      if (e.key === "ArrowUp") {
+        e.preventDefault();
+        setSelectedIdx((i) => (i - 1 + filtered.length) % filtered.length);
+        return;
+      }
+      if (e.key === "Enter" || e.key === "Tab") {
+        e.preventDefault();
+        insertMention(filtered[selectedIdx]);
+        return;
+      }
+      if (e.key === "Escape") {
+        e.preventDefault();
+        setShowDropdown(false);
+        return;
+      }
+    }
+
+    if (e.key === "Enter" && !e.shiftKey && !showDropdown) {
+      e.preventDefault();
+      onSubmit();
+    }
+  };
+
+  const ICON: Record<string, string> = { human: "👤", agent: "🤖" };
+
+  return (
+    <div className="relative flex-1">
+      <textarea
+        ref={inputRef}
+        value={value}
+        onChange={handleChange}
+        onKeyDown={handleKeyDown}
+        placeholder={placeholder}
+        disabled={disabled}
+        rows={1}
+        className="w-full bg-[var(--bg)] border border-[var(--border)] rounded-lg px-4 py-2 text-sm outline-none focus:border-[var(--accent)] resize-none"
+        style={{ minHeight: "38px", maxHeight: "120px" }}
+        onInput={(e) => {
+          const el = e.currentTarget;
+          el.style.height = "auto";
+          el.style.height = Math.min(el.scrollHeight, 120) + "px";
+        }}
+      />
+      {showDropdown && filtered.length > 0 && (
+        <div
+          ref={dropdownRef}
+          className="absolute bottom-full left-0 mb-1 w-64 bg-[var(--surface)] border border-[var(--border)] rounded-lg shadow-lg overflow-hidden z-50"
+        >
+          {filtered.map((m, i) => (
+            <button
+              key={m.id}
+              className={`w-full text-left px-3 py-2 text-sm flex items-center gap-2 hover:bg-white/10 ${
+                i === selectedIdx ? "bg-white/10" : ""
+              }`}
+              onMouseDown={(e) => {
+                e.preventDefault(); // prevent blur
+                insertMention(m);
+              }}
+            >
+              <span>{ICON[m.type] || "👤"}</span>
+              <span className="font-medium">{m.name}</span>
+              <span className="text-[var(--muted)]">@{m.slug}</span>
+            </button>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}

src/pages/ProjectPage.tsx

@@ -101,7 +101,7 @@ export default function ProjectPage() {
             <KanbanBoard projectId={project.id} projectSlug={project.slug} />
           )}
           {activeTab === "chat" && project.chat_id && (
-            <ChatPanel chatId={project.chat_id} />
+            <ChatPanel chatId={project.chat_id} projectSlug={project.slug} />
           )}
           {activeTab === "chat" && !project.chat_id && (
             <div className="flex items-center justify-center h-full text-[var(--muted)] text-sm">