Fix HOME volume mount, genericize topic, add progress statuses, extract lexicon

- Volume was mounted at ~/.claude only, but claude-code writes auth to
  ~/.claude.json too — that file lived on the ephemeral container layer and
  was lost on every recreate. Now the whole $HOME is on the named volume,
  and claude-config moved outside HOME (/app) so it isn't shadowed by it.
- Default /news topic was hardcoded to AI; now it's a configurable
  DEFAULT_TOPIC (plain "главные новости дня"), topic is fully free-form.
- Prompt now instructs Claude to send interim "⏳ ..." progress updates via
  send_to_telegram while researching, not just the final digest — a bare
  request like "call this tool" was already taking 3+ minutes end-to-end,
  so silence read as broken.
- All user-facing/prompt text moved into bot/lib/lexicon.dart.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

bot/bin/agent_news_bot.dart

@@ -3,6 +3,7 @@ import 'dart:io';
 import '../lib/config.dart';
 import '../lib/telegram.dart';
 import '../lib/claude_runner.dart';
+import '../lib/lexicon.dart';
 
 void main() async {
   final config = Config.fromEnv();
@@ -41,12 +42,10 @@ void main() async {
         continue;
       }
 
+      stderr.writeln('[$chatId] $text');
+
       if (text == '/start') {
-        await telegram.sendMessage(
-          chatId,
-          'Привет! Я agent-news. Команда /news — свежая выжимка по ИИ '
-          '(ресёрч делает Claude Code, займёт 1-3 минуты).',
-        );
+        await telegram.sendMessage(chatId, Lexicon.welcome);
         continue;
       }
 
@@ -54,17 +53,13 @@ void main() async {
         final topic = text.startsWith('/news ') ? text.substring(6).trim() : null;
 
         if (claude.isBusy) {
-          await telegram.sendMessage(chatId, 'Уже выполняю другой запрос, подожди.',
-              replyToMessageId: messageId);
+          await telegram.sendMessage(chatId, Lexicon.alreadyBusy, replyToMessageId: messageId);
           continue;
         }
 
-        await telegram.sendMessage(
-          chatId,
-          '🔎 Ищу свежую информацию${topic != null ? ' по теме «$topic»' : ' по ИИ'}, '
-          'это займёт пару минут…',
-          replyToMessageId: messageId,
-        );
+        final effectiveTopic = (topic == null || topic.isEmpty) ? config.defaultTopic : topic;
+        await telegram.sendMessage(chatId, Lexicon.starting(effectiveTopic),
+            replyToMessageId: messageId);
         await telegram.sendTyping(chatId);
 
         unawaited(_runNews(claude, telegram, chatId, topic));
@@ -88,11 +83,12 @@ Future<void> _runNews(
     case ClaudeOutcome.busy:
       break; // уже сообщили выше
     case ClaudeOutcome.timeout:
-      await telegram.sendMessage(chatId, 'Не успел уложиться по времени, попробуй позже.');
+      stderr.writeln('news for $chatId timed out');
+      await telegram.sendMessage(chatId, Lexicon.timedOut);
       break;
     case ClaudeOutcome.failure:
       stderr.writeln('news for $chatId failed: ${result.detail}');
-      await telegram.sendMessage(chatId, 'Не получилось выполнить ресёрч, попробуй позже.');
+      await telegram.sendMessage(chatId, Lexicon.failed);
       break;
   }
 }