Add SQLite database for Telegram bot user/group settings

- Replace Redis/in-memory storage with SQLite for persistence
- Add database.ts service with tables for users, groups, purchases, participants
- Update state.ts and groupState.ts to use SQLite backend
- Fix buyer_name to use display name instead of Telegram ID
- Remove legacy reminder array handlers (now using 3-slot system)
- Add better-sqlite3 dependency, remove ioredis
- Update env.example with BOT_DATABASE_PATH option
- Add data/ directory to .gitignore for database files

telegram_bot/src/handlers/start.ts

@@ -1,7 +1,7 @@
 import TelegramBot from 'node-telegram-bot-api';
 import { stateManager } from '../services/state';
 import { logger, logUserAction } from '../services/logger';
-import { getMainMenuKeyboard, getCancelKeyboard } from '../utils/keyboards';
+import { getMainMenuKeyboard, getLightningAddressKeyboard } from '../utils/keyboards';
 import { messages } from '../messages';
 
 /**
@@ -10,6 +10,7 @@ import { messages } from '../messages';
 export async function handleStart(bot: TelegramBot, msg: TelegramBot.Message): Promise<void> {
   const chatId = msg.chat.id;
   const userId = msg.from?.id;
+  const username = msg.from?.username;
   
   if (!userId) {
     await bot.sendMessage(chatId, messages.errors.userNotIdentified);
@@ -17,7 +18,7 @@ export async function handleStart(bot: TelegramBot, msg: TelegramBot.Message): P
   }
 
   logUserAction(userId, 'Started bot', {
-    username: msg.from?.username,
+    username: username,
     firstName: msg.from?.first_name,
   });
 
@@ -29,7 +30,7 @@ export async function handleStart(bot: TelegramBot, msg: TelegramBot.Message): P
       // Create new user
       user = await stateManager.createUser(
         userId,
-        msg.from?.username,
+        username,
         msg.from?.first_name,
         msg.from?.last_name
       );
@@ -40,9 +41,9 @@ export async function handleStart(bot: TelegramBot, msg: TelegramBot.Message): P
 
     // Check if lightning address is set
     if (!user.lightningAddress) {
-      await bot.sendMessage(chatId, messages.start.needAddress, { 
+      await bot.sendMessage(chatId, messages.start.needAddressWithOptions(username), { 
         parse_mode: 'Markdown',
-        reply_markup: getCancelKeyboard(),
+        reply_markup: getLightningAddressKeyboard(username),
       });
       
       await stateManager.updateUserState(userId, 'awaiting_lightning_address');