fix(scan): honour ?network= on home + list + leaderboard pages

[satyakwok]

Summary

Deep audit found 22 client-side pages calling useNetwork() without the matching useNetworkFromQuery() hook. Result: deeplinks like https://scan.sentrixchain.com/blocks?network=testnet (the V1 mainnet host with a network query override) rendered mainnet data because the network cookie never flipped on first load.

Detail pages (blocks/[height], tx/[hash], address/[addr], tokens/[addr]) were correct. Everything else — home, blocks list, validators, tokens list, leaderboard subpages, search, sentinel, accounts, gas, supply, epochs, contracts, mempool, analytics, api-docs, forks — missed the hook.

Why this matters when each network has its own subdomain

Canonical access is via dedicated subdomain, not the query string:

Network	V1 (Next.js scan, this PR)	V2 (Leptos / Obsidian)
Mainnet	scan.sentrixchain.com	scan.sentriscloud.com
Testnet	scan-testnet.sentrixchain.com	scan-testnet.sentriscloud.com

The ?network= query exists as a cross-domain fallback for inbound deeplinks from other apps that aren't network-aware (faucet success page, wallet notifications, partner emails — all places where a single template URL gets reused with a network suffix). Without this fix, those links land on the right domain but the wrong cookie, so the user sees a network mismatch on first paint.

Reproduction (pre-fix, verified live)

GET https://scan.sentrixchain.com/blocks?network=testnet
→ page renders block heights around 1,681,800  (V1 mainnet's actual chain tip)
   instead of around 3,172,785                 (V1 testnet's actual chain tip)

The cookie carried mainnet, the URL hinted testnet, the page rendered with the cookie's network and ignored the URL hint.

Fix

One-line call to useNetworkFromQuery() after each useNetwork() call site, with a consistent comment so future pages follow the pattern:

const { network } = useNetwork();
// Deeplink network switch.
useNetworkFromQuery();

22 files modified, all in apps/scan/app/[locale]/.

Verification

• pnpm --filter @sentriscloud/scan typecheck clean
• After deploy: https://scan.sentrixchain.com/blocks?network=testnet shows testnet block heights (~3.17M), not mainnet.
• The dedicated https://scan-testnet.sentrixchain.com/... flow is unchanged — that path was never broken.

Related work today

• chore(audit-live): add V2 (Leptos) explorer to surface #54 audit-live V2 coverage (merged)
• fix(scan): probe block-by-hash for 64-hex search queries #55 search probe block-by-hash (merged)
• fix(scan): stop chain-walk fanout + route /rpc to correct host #56 stop chain-walk fanout + correct host (merged)
• This PR fix(scan): honour ?network= on home + list + leaderboard pages #57 deeplink network switch on list pages

Test plan

• CI green
• https://scan.sentrixchain.com/blocks?network=testnet lists testnet blocks (~3.17M heights), not mainnet
• Cookie state persists after one cross-network deeplink visit
• Dedicated-subdomain flow (scan-testnet.sentrixchain.com) still works as before