fix: exercise list missing in History when single session auto-expands

[ChristopherRotnes]

$(cat <<'EOF'

Summary

• loadSession auto-expanded single-session days by calling setExpandedIds but never called initSessionEdit, so edit.exercises stayed undefined and the exercise list rendered nothing
• The body map showed correctly because it reads directly from raw session data — only the exercise list depends on edit state
• Fixed by calling initSessionEdit alongside setExpandedIds in the single-session auto-expand branch

Test plan

• Navigate to History and select a day with exactly one session — exercise list should now be visible below the muscle chips
• Select a day with multiple sessions — manually expanding one should still show the exercise list (existing path, should be unaffected)
• Verify the body map still renders correctly in both cases

https://claude.ai/code/session_01NwKrrVkWKrzCNzTnEdBqwK
EOF
)

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Generated by Claude Code

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