fix(contacts-ui): show specific add-by-email errors

docs/core-checklist-status.md

@@ -10,7 +10,7 @@ Legend:
 1. Account - `PARTIAL` (email auth, JWT, refresh, logout, reset; sessions exist, full UX still improving)
 2. User Profile - `DONE` (username, name, avatar, bio, update)
 3. User Status - `PARTIAL` (online/last seen/offline; web now formats `just now/today/yesterday/recently`, backend-side presence heuristics still limited)
-4. Contacts - `PARTIAL` (list/search/add/remove/block/unblock; `add by email` flow covered by integration tests including `success/not found/blocked conflict`; UX moved to menu)
+4. Contacts - `PARTIAL` (list/search/add/remove/block/unblock; `add by email` flow covered by integration tests including `success/not found/blocked conflict`; web now surfaces specific add-by-email errors (`not found` vs `blocked`); UX moved to menu)
 5. Chat List - `DONE` (all/pinned/archive/sort/unread; saved-messages delete behavior covered: clear history without deleting chat)
 6. Chat Types - `DONE` (private/group/channel)
 7. Chat Creation - `DONE` (private/group/channel)

web/src/components/ChatList.tsx

@@ -1,5 +1,6 @@
 import { useEffect, useRef, useState } from "react";
 import { createPortal } from "react-dom";
+import axios from "axios";
 import { archiveChat, clearChat, createPrivateChat, deleteChat, getChats, getSavedMessagesChat, joinChat, leaveChat, pinChat, unarchiveChat, unpinChat } from "../api/chats";
 import { globalSearch } from "../api/search";
 import type { DiscoverChat, Message, UserSearchItem } from "../chat/types";
@@ -526,8 +527,20 @@ export function ChatList() {
                     await addContactByEmail(email);
                     setContactEmail("");
                     setContacts(await listContacts());
-                  } catch {
-                    setContactEmailError("User with this email not found");
+                    setContactEmailError(null);
+                  } catch (error) {
+                    if (axios.isAxiosError(error)) {
+                      const status = error.response?.status;
+                      if (status === 404) {
+                        setContactEmailError("User with this email not found");
+                        return;
+                      }
+                      if (status === 409) {
+                        setContactEmailError("Cannot add contact while blocked");
+                        return;
+                      }
+                    }
+                    setContactEmailError("Failed to add contact");
                   }
                 }}
                 type="button"