Add strategy plugin Telegram alert channel

[Pigbibi]

Summary

• add provider-neutral Telegram Bot API delivery for strategy plugin alerts
• include Telegram in the alert dispatcher, marker stores, summaries, and public exports
• document the new channel and bump package version to 0.7.30

Tests

• PYTHONPATH=src pytest tests/test_telegram.py tests/test_strategy_plugin_telegram_notifications.py tests/test_strategy_plugin_alert_dispatcher.py tests/test_strategy_plugins.py -q
• PYTHONPATH=src ruff check .

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Validate Telegram API ok before reporting success

_request_succeeded currently treats any HTTP 2xx as a successful delivery and never inspects the response JSON, even though Telegram responses include an ok field to indicate application-level success. If the API (or a proxy/self-hosted Bot API endpoint) returns HTTP 200 with ok: false, this path marks the send as successful; downstream, publish_strategy_plugin_telegram_alerts can record the alert marker and skip future retries, causing real alert drops.

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