Pool transactions: clearer table and infinite scroll

[Jiangzhewen]

Summary

• Add a paginated getPoolTransactions API path using the existing dataEndpoint and /pool/transactions endpoint.
• Add pool transaction stores and a default page size shared by the API and UI.
• Render a clearer pool transactions table below the pool stats, including type, asset, amount, pool balance, buffer balance, market/user context, timestamp, and transaction links.
• Load additional pages when the table scroll reaches the bottom.

Validation

• npm ci
• npm run build
• Browser validation on http://127.0.0.1:5000/pool
• Playwright route mock for /pool/transactions verified 50 initial rows and scroll append to 75 rows.

Note: in this local environment, https://data.cap.io requests fail during TLS setup and the existing Alchemy key returns 403, so live API/RPC responses could not be validated from this machine. The mocked browser check only replaced the pool transactions API response.

Closes #29

[Jiangzhewen]

Local validation completed:\n\n- npm ci\n- npm run build\n- Browser check on /pool with a Playwright route mock for /pool/transactions: verified 50 initial rows and append to 75 after scrolling.\n\nThe Vercel check is currently failing with "Account is blocked", which appears unrelated to this code change.

[Jiangzhewen]

Vercel is failing before it reaches the project build with Account is blocked and links to Vercel's account-blocked help page, so this appears to be an account/deployment permission issue rather than a code failure. I re-ran npm run build locally on the current PR head and it completes successfully; the output only contains the existing Rollup/Svelte warnings already present in this project.