fix(explorer): allow authenticated nextfork RPC override

[decofe]

Summary

• add a server-only TEMPO_NEXTFORK_RPC_URL env var for the nextfork explorer RPC
• for nextfork server-side RPC calls, prefer that authenticated direct RPC URL instead of the proxy returning null receipts
• keep browser traffic on the RPC proxy and preserve existing RPC behavior for non-nextfork explorers

Deployment note

Set TEMPO_NEXTFORK_RPC_URL for the nextfork explorer Cloudflare Worker to the authenticated nextfork RPC URL. Do not commit the credential.

Validation

• git diff --check
• corepack pnpm --filter explorer check:types could not run because Corepack timed out downloading pinned pnpm@10.33.0 from npm in this sandbox.

Prompted by: @0xrusowsky

[github-actions]

Bundle Size Report

Metric	Size	Δ Change
Total	5.1 MB	+859.8 KB (+19.8%)
Gzip	1.5 MB	+242.5 KB (+19.4%)
Brotli	1.3 MB	+212.3 KB (+19.5%)

Chunk changes (>1KB)

Chunk	Change
assets/chains.js (removed)	-360.7 KB
assets/export-rate-limit.js (removed)	-177.3 KB
assets/decodeAbiParameters.js (removed)	-71.7 KB
assets/AbiItem.js (removed)	-27.1 KB
assets/Bytes.js (removed)	-25.8 KB
assets/env.js	-9.4 KB
assets/validators.js (removed)	-5.1 KB
assets/wagmi.config.js	-3.9 KB
assets/readContracts.js (removed)	-2.7 KB
assets/_hash.js	+1.6 KB
assets/chevron-down.js (new)	+1.6 KB
assets/.js	+1.6 KB
assets/queryOptions.js	+1.9 KB
assets/tokenlist.js	+1.9 KB
assets/known-event-totals.js (new)	+2.1 KB
assets/router.js	+2.2 KB
assets/_address.js	+2.4 KB
assets/Address.js	+3.4 KB
assets/call.js	+3.8 KB
assets/Errors.js (new)	+3.9 KB
...and 14 more

Compared against main branch (baseline from 4/27/2026, 4:02:54 PM)

[github-actions]

Cloudflare Deployments

App	Environment	Status	Preview
explorer	devnet	[OK] Deployed	View Preview
explorer	mainnet	[OK] Deployed	View Preview
explorer	nextfork	[OK] Deployed	View Preview
explorer	testnet	[OK] Deployed	View Preview
fee-payer	devnet	[>>] Skipped	No changes
fee-payer	moderato	[>>] Skipped	No changes
fee-payer	privy	[>>] Skipped	No changes
og	-	[>>] Skipped	No changes
reth-snapshots-viewer	-	[>>] Skipped	No changes
tempo-snapshots-viewer	-	[>>] Skipped	No changes
tokenlist	-	[>>] Skipped	No changes