Show own stats at top of friends stats page

[jhurwitz]

Summary

• Adds the current user's own stats card (friend count, lifetime oys sent, lifetime oys received) at the top of the friends stats page
• The self card omits fields that don't apply to yourself: last oy timestamp, streak, nickname, unfriend, block, and report
• Self stats are fetched in parallel with friend profiles in a single API call

Test plan

• Open the friends stats page and verify your own stats card appears at the top
• Verify the self card shows username, friend count, lifetime oys sent, and lifetime oys received
• Verify the self card does not show last oy, streak, nickname input, or action buttons
• Verify friend cards below still render and function correctly

🤖 Generated with Claude Code

[phulin]

approved without review