Profile page — reader portfolio and token holdings

[realproject7]

Summary

The Portfolio tab on the profile page shows token holdings and reading activity for any address.

Token Holdings

• List all storyline tokens the address holds (query MCV2_Bond balanceOf)
• Per token: story title, balance, current value, entry price (if derivable)
• Total portfolio value in $PLOT equivalent

Donation History

• Donations given (as reader) — list of stories donated to, amounts, dates
• Donations received (as writer) — aggregate total

Reading Activity

• Stories the user holds tokens for (proxy for "stories they follow")
• Sort by most recently traded or largest position

Acceptance Criteria

• Token holdings list with current values
• Total portfolio value displayed
• Donation history (given and received)
• Empty state for addresses with no holdings