Add performance profiling and list virtualization for large membership sets

[Lakes41]

• Difficulty: Advanced
• Type: performance
• Background: The membership dashboard renders "all your active guild memberships and assigned roles in a unified dashboard," but power users (e.g., members of dozens of guilds) may experience degraded scroll performance if the list isn't virtualized/optimized.
• Expected outcome: Dashboard and guild lists scroll smoothly (60fps target) with large synthetic datasets (e.g., 200+ guilds), using proper virtualization and memoization.
• Suggested implementation: Profile current list rendering with Flipper/React DevTools; migrate to FlashList (or optimize existing FlatList usage) with getItemLayout/estimatedItemSize; memoize list item components and avoid inline function props causing re-renders.
• Acceptance criteria: A documented before/after performance comparison (frame drop count or render time) with a large synthetic dataset; no functional regressions in existing list interactions; test fixture generator for large datasets added under tests/.
• Likely affected files/directories: app/ (dashboard/list screens), src/, tests/
• Labels: performance, GrantFox OSS, Maybe Rewarded, Official Campaign | FWC26

[ghg001]

Hi maintainer,I'll profile the current list rendering to identify bottlenecks, optimize it with virtualization (FlashList or an improved FlatList setup), memoize list items to reduce unnecessary re-renders, and validate the improvements with performance benchmarks and large dataset test fixtures.

[grantfox-oss]

🦊 GrantFox — @ghg001 has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #103)
2. Your PR will be reviewed by the Adamantine-guild maintainers

Good luck! Track your progress on GrantFox.