Refactor to apps/ structure

JIGAIDO is now a platform with apps/ as the container.
All telegram-bot files moved to apps/telegram-bot/:
- bot.py, commands.py, cron.py, db.py, schema.sql
- requirements.txt, .env.example, README.md
- Root now holds SPEC.md, README.md, CONTRIBUTING.md only.

Structure:
jigaido/
├── apps/
│   └── telegram-bot/
└── SPEC.md, README.md, CONTRIBUTING.md

apps/telegram-bot/bot.py

@@ -0,0 +1,78 @@
+"""JIGAIDO Telegram bot entrypoint."""
+
+import logging
+import os
+import sys
+
+from telegram import Update
+from telegram.ext import (
+    Application,
+    CommandHandler,
+    MessageHandler,
+    filters,
+)
+
+import db
+import commands
+
+logging.basicConfig(
+    format="%(asctime)s %(levelname)s %(name)s: %(message)s",
+    level=logging.INFO,
+)
+log = logging.getLogger(__name__)
+
+# Token from environment or config
+BOT_TOKEN = os.environ.get("JIGAIDO_BOT_TOKEN", "")
+
+
+def build_app() -> Application:
+    app = Application.builder().token(BOT_TOKEN).build()
+
+    # Core commands
+    app.add_handler(CommandHandler("start", commands.cmd_start))
+    app.add_handler(CommandHandler("help", commands.cmd_help))
+    app.add_handler(CommandHandler("bounty", commands.cmd_bounty))
+    app.add_handler(CommandHandler("my", commands.cmd_my))
+    app.add_handler(CommandHandler("add", commands.cmd_add))
+    app.add_handler(CommandHandler("update", commands.cmd_update))
+    app.add_handler(CommandHandler("delete", commands.cmd_delete))
+    app.add_handler(CommandHandler("track", commands.cmd_track))
+    app.add_handler(CommandHandler("untrack", commands.cmd_untrack))
+    app.add_handler(CommandHandler("admin_add", commands.cmd_admin_add))
+    app.add_handler(CommandHandler("admin_remove", commands.cmd_admin_remove))
+
+    # Fallback: unknown commands
+    app.add_handler(MessageHandler(filters.COMMAND, commands.cmd_help))
+
+    return app
+
+
+async def post_init(app: Application) -> None:
+    # Set bot commands in menu
+    await app.bot.set_my_commands([
+        ("bounty", "List bounties"),
+        ("my", "Your tracked bounties"),
+        ("add", "Add a bounty"),
+        ("track", "Track a bounty"),
+        ("untrack", "Stop tracking"),
+        ("help", "Show help"),
+    ])
+
+
+def main() -> None:
+    if not BOT_TOKEN:
+        log.error("JIGAIDO_BOT_TOKEN environment variable not set.")
+        sys.exit(1)
+
+    db.init_db()
+    log.info("Database initialized.")
+
+    app = build_app()
+    app.post_init = post_init
+
+    log.info("JIGAIDO starting...")
+    app.run_polling(drop_pending_updates=True)
+
+
+if __name__ == "__main__":
+    main()