feat: implement /timezone command to get/set room timezone

Re-implement the timezone command that was reverted.

- Add cmd_timezone function with get/set functionality
- Validate timezone using zoneinfo (IANA format)
- Admin-only permission via service layer
- Update help text and bot command list
- Fix indentation bug in cmd_add (duplicate lines)

Fixes #53

apps/telegram-bot/commands.py

@@ -3,6 +3,7 @@
 import time
 from functools import wraps
 from typing import Optional
+from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
 
 import dateparser
 from telegram import Update
@@ -19,7 +20,6 @@ TRACKING_SERVICE = TrackingService(TRACKING_STORAGE, ROOM_STORAGE)
 TELEGRAM_BOT_USERNAME = "your_bot_username"
 
 
-
 def extract_args(text: str) -> list[str]:
     if not text:
         return []
@@ -241,9 +241,7 @@ async def cmd_add(update: Update, ctx: ContextTypes.DEFAULT_TYPE) -> None:
 
     due_str = ""
     if due_date_ts:
-    due_str = ""
-    if due_date_ts:
-        due_str = f" | Due: {time.strftime("%Y-%m-%d", time.localtime(due_date_ts))}"
+        due_str = f" | Due: {time.strftime('%Y-%m-%d', time.localtime(due_date_ts))}"
     await update.message.reply_text(
         f"✅ Bounty added (#{bounty.id}){due_str}",
         disable_web_page_preview=True,
@@ -458,6 +456,35 @@ async def cmd_show(update: Update, ctx: ContextTypes.DEFAULT_TYPE) -> None:
     await update.message.reply_text("\n".join(lines), disable_web_page_preview=True)
 
 
+async def cmd_timezone(update: Update, ctx: ContextTypes.DEFAULT_TYPE) -> None:
+    args = extract_args(update.message.text)
+    room_id = get_room_id(update)
+    user_id = get_user_id(update)
+
+    if not args:
+        current_tz = BOUNTY_SERVICE.get_timezone(room_id)
+        await update.message.reply_text(f"Current timezone: {current_tz}")
+        return
+
+    timezone_str = args[0]
+
+    try:
+        ZoneInfo(timezone_str)
+    except (KeyError, ZoneInfoNotFoundError):
+        await update.message.reply_text(
+            "⛔ Invalid timezone. Use IANA format (e.g., Asia/Jakarta)"
+        )
+        return
+
+    try:
+        BOUNTY_SERVICE.set_timezone(room_id, timezone_str, user_id)
+    except PermissionError as e:
+        await update.message.reply_text(f"⛔ {e}")
+        return
+
+    await update.message.reply_text(f"✅ Timezone set to {timezone_str}.")
+
+
 async def cmd_help(update: Update, ctx: ContextTypes.DEFAULT_TYPE) -> None:
     await update.message.reply_text(
         "👻 JIGAIDO Commands:\n\n"
@@ -472,9 +499,9 @@ async def cmd_help(update: Update, ctx: ContextTypes.DEFAULT_TYPE) -> None:
         "/track <id> — track a bounty (groups only)\n"
         "/untrack <id> — stop tracking (groups only)\n"
         "/show <id> — show bounty details\n"
+        "/timezone — get room timezone\n"
+        "/timezone <tz> — set room timezone (admin only)\n"
         "/start — re-initialize\n"
         "/help — this message",
         disable_web_page_preview=True,
     )
-
-