Document scenario epic migration

[shchukins]

Summary

• Documents the conservative scenario-epic migration in docs/product/SCENARIO_EPIC_MIGRATION.md
• Records the six new top-level scenario epics created in GitHub: [SCENARIO] Morning Readiness Loop #91-[SCENARIO] Research Sandbox #96
• Records the additive migration comments added to [EPIC] Unified Load Model #9, [EPIC] Athlete Profile #16, [EPIC] Equipment & maintenance system #17, [EPIC] Bike Profile #18, [Research] Automated model experimentation sandbox (autoresearch-like loop) #36, [EPIC] Metrics layer & explainability (Athlytics-inspired) #56, [EPIC] Adaptive Feedback Loop #73, and [EPIC] Unified Subjective Feedback Model #82

GitHub issue changes performed

Created:

• [SCENARIO] Morning Readiness Loop #91 [SCENARIO] Morning Readiness Loop
• [SCENARIO] Explainable Readiness Experience #92 [SCENARIO] Explainable Readiness Experience
• [SCENARIO] Ride Preparation and Recommendation Loop #93 [SCENARIO] Ride Preparation and Recommendation Loop
• [SCENARIO] Post-Workout Feedback Loop #94 [SCENARIO] Post-Workout Feedback Loop
• [SCENARIO] Readiness Calibration Loop #95 [SCENARIO] Readiness Calibration Loop
• [SCENARIO] Research Sandbox #96 [SCENARIO] Research Sandbox

Conservative comments only:

• [EPIC] Unified Load Model #9, [EPIC] Athlete Profile #16, [EPIC] Equipment & maintenance system #17, [EPIC] Bike Profile #18, [Research] Automated model experimentation sandbox (autoresearch-like loop) #36, [EPIC] Metrics layer & explainability (Athlytics-inspired) #56, [EPIC] Adaptive Feedback Loop #73, [EPIC] Unified Subjective Feedback Model #82

No issues were closed, renamed, deleted, or relabeled. Completed issues were not modified.

Notes

This PR is stacked on #90 because docs/product/END_TO_END_EPICS_PROPOSAL.md exists on product/end-to-end-epics-proposal locally, not on main yet.

Verification

• Confirmed no open scenario epics with the requested exact titles existed before creation
• Checked repo auto-label/project-adjacent structure (.github/workflows/auto-label.yml)
• Documentation-only repo change; no tests run