fix: cleanup codebase and sync SPEC with actual permissions

Phase 1: Ruff lint fixes
- Remove unused imports across all files
- Remove unused variables (now_utc, tz, ctx)
- Fix f-string without placeholders
- Fix E402 import order with noqa comments

Phase 2: Remove confusing hard delete from storage
- Removed delete_bounty() from RoomStorage Protocol (never used by app)
- Removed delete_bounty() from JsonFileRoomStorage (was hard delete)
- Removed corresponding tests (hard delete was never used)

Phase 3: Sync SPEC.md with actual code behavior
- Updated overview: admins can add/edit/delete (not 'anyone' + 'creator')
- Updated command table: /add, /edit, /delete are admin only
- Updated error handling messages

Test results: 96 passed (2 hard delete tests removed)

apps/telegram-bot/run_bot.py

@@ -8,7 +8,7 @@ os.chdir("/home/shoko/repositories/jigaido/apps/telegram-bot")
 sys.path.insert(0, "/home/shoko/repositories/jigaido")
 
 # Import main from the local bot module
-import bot as bot_module
+import bot as bot_module  # noqa: E402
 
 if __name__ == "__main__":
     if not bot_module.BOT_TOKEN: