Two related Telegram changes:
1. Per-chat command localization. setMyCommands now accepts a scope
(BotCommandScopeChat) and deleteMyCommands clears scoped bindings.
Command registration runs three tiers: default → per-language
(Telegram client language) → per-chat (UI override). Saving a
chat's language_override or commands_enabled toggle pushes the
binding to Telegram inline rather than waiting on the 30s
debounced bot-wide sync.
2. Unified Telegram locale resolution. Three test paths (bot test_chat,
target receiver test, target-level fan-out) used to disagree on
locale priority — the target receiver test in particular only
consulted receiver.locale and ignored the chat's language_override.
Introduced pick_telegram_locale (pure) and
resolve_telegram_chat_locale (async DB lookup) in services/notifier
so all three paths share one priority order:
receiver.locale → chat.language_override → chat.language_code → fallback
Fan-out keeps batch-loading TelegramChat rows for efficiency, just
runs them through the same priority function now.
alexei.dolgolyov
ef942b77cc