Add Coinalyze crypto market regime context

[hanchiang]

Summary

• add Coinalyze-backed BTC perpetual market-regime collection for crypto signal Phase 2A
• persist raw per-market and aggregate market-regime snapshots/metrics, then surface the aggregate context in private operator output
• keep collection disabled by default and provider-gated; public crypto digest remains fail-open if optional regime collection fails
• pin backend to released market-data-library tag 1.6.0

Notes

• Coinalyze symbols must resolve through futures metadata as BTC perpetual markets before storage.
• Intraday backfill is capped against Coinalyze retention constraints.
• Current rate limiting is handled in market-data-library per CoinalyzeService instance; future multi-worker or multi-consumer usage with the same key should add shared limiter state.
• CryptoQuant remains limited to the existing Basic-plan-compatible manual price OHLCV route and is not used for market-regime collection.

Validation

• ./scripts/show_market_data_library_source.sh -> git-installed-package, imported from .venv/site-packages
• PYTHONPATH="$(pwd)" RUFF_CACHE_DIR=/tmp/ruff-cache-market-data-backend poetry run ruff check ... for touched backend Python files
• PYTHONPATH="$(pwd)" poetry run pytest tests/unit -> 266 passed, 4 existing warnings
• git diff --check
• released-package no-send E2E smoke with live Coinalyze calls, temp SQLite DB, no Telegram sends