fix(tracker): include resolution activity in trader stats

[cgfixit]

Summary

• Request TRADE, REDEEM, and REWARD activity in the tracker stats fetch.
• Keep the existing redemption-aware scorer reachable for buy-and-hold positions.
• Update the request-contract test.

Why

TrackerClient._compute_trader_stats already handles redemption rows, but _fetch_activity requested only TRADE, so resolution activity could not reach that scorer. The current Polymarket activity API exposes these activity types.

Verification

• python -m pytest tests/test_tracker.py -q -p no:cacheprovider — 49 passed
• python -m pytest -m "not integration" -q -p no:cacheprovider — 624 passed
• powershell -NoProfile -ExecutionPolicy Bypass -File scripts/check-lint.ps1
• python -m mypy polymarket_copier --ignore-missing-imports --no-strict-optional
• python -m py_compile polymarket_copier/core/tracker.py tests/test_tracker.py
• git diff --check

Scope and risk

Stats fetching only. Monitor trade polling and the live-mode hard-disable are unchanged. No credentials or live execution were used.