feat: add replay calibration and exit timing analysis

[user040131]

Summary

• add deterministic replay calibration reviews for each replay day and a weekly calibration summary
• add a new replay_calibrator role for optional model-augmented replay drift analysis
• add 5-minute-bar based exit timing analysis so replay can show the best sell timing versus close hold
• render weekly calibration, daily mismatch drivers, and exit timing insights in the replay lab UI

Verification

• & ''.\services\api\.venv\Scripts\python.exe'' -m pytest services/api/tests/test_weekly_replay.py services/api/tests/test_replay_analysis_helpers.py -q
• & ''.\services\api\.venv\Scripts\python.exe'' -m compileall services/api/app services/api/tests
• & ''.\node_modules\.bin\tsc.CMD'' --noEmit (workdir: apps/web)
• @'' ... WeeklyReplayService import smoke check ... ''@ | & ''.\.venv\Scripts\python.exe'' - (workdir: services/api)

Notes

• The weekly replay endpoint was not live in this sandbox during verification, so live HTTP response validation was not re-run here.
• When an OpenAI API key is configured, the new replay_calibrator role augments the deterministic weekly summary; without a key the feature still works deterministically.

Closes #30
Closes #31