The composer completes mentions and hashtags

A mention or hashtag being written at the end of the words is offered, once typing pauses, the accounts or tags
PrivaPub already knows (/api/v2/search, never resolving); a click writes it out. e2e: a town persona's handle,
begun, is offered and completed. CLAUDE.md also says that FEP-5624's moderated comments (PeerTube) show as pending
on a card, as GoToSocial's policies do.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

Services/AccountService.cs

@@ -193,6 +193,20 @@ namespace decePubClient.Services
 			return new SearchResults();
 		}
 
+		/// <summary>Accounts or hashtags this server already knows that match what is being typed, for the composer: nothing
+		/// is fetched from elsewhere.</summary>
+		public async Task<SearchResults> Suggest(string typed, bool hashtags, CancellationToken cancellationToken = default)
+		{
+			using var response = await httpService.Get(APIs.Mastodon.GET_Search,
+				[$"q={Uri.EscapeDataString(typed)}", $"type={(hashtags ? "hashtags" : "accounts")}", "resolve=false", "limit=5"],
+				cancellationToken: cancellationToken);
+			if (response.IsSuccessStatusCode)
+				return await response.MastodonReadFromJsonAsync<SearchResults>(cancellationToken) ?? new SearchResults();
+
+			await LogFailure(response, nameof(Suggest), cancellationToken);
+			return new SearchResults();
+		}
+
 		/// <summary>Saves the persona's profile; Data is its account as PrivaPub now describes it (with its Source).</summary>
 		public async Task<WebResult> UpdateProfile(ProfileForm form, CancellationToken cancellationToken = default)
 		{