feat(explorer): show expiring nonce label and expiry timestamp

[decofe]

Summary

Improves how expiring nonces (TIP-1009) are displayed in the explorer.

Changes

• Overview tab: Nonce row now shows "Expiring" (linked to TIP-1009 docs) with the validBefore expiry timestamp instead of showing two separate rows for nonce key and nonce value
• Raw tab: Annotates the nonceKey field with (expiring nonce) when it equals uint256.max, and annotates validBefore with a human-readable ISO timestamp

Example tx: https://explore.mainnet.tempo.xyz/tx/0x7bc04ba930b4c12061f57abc0d1e095564cacce56b02eda38c7cdf007d440f7d?tab=raw

Co-Authored-By: zhygis 5236121+Zygimantass@users.noreply.github.com

Prompted by: zygis

[github-actions]

Bundle Size Report

Metric	Size	Δ Change
Total	5.1 MB	+294.8 KB (+6.0%)
Gzip	1.4 MB	+144.5 KB (+10.8%)
Brotli	1.2 MB	+120.9 KB (+10.5%)

Chunk changes (>1KB)

Chunk	Change
assets/KeyManager.js (removed)	-477.4 KB
assets/QueryBuilder.js (removed)	-423.4 KB
assets/Intro.js (removed)	-66.0 KB
assets/createSsrRpc.js (removed)	-43.8 KB
assets/Hash.js (removed)	-31.0 KB
assets/_layout.js	-21.4 KB
assets/stringify.js (removed)	-19.7 KB
assets/isAddressEqual.js	-18.4 KB
assets/address.js	-14.1 KB
assets/Address.js	-13.1 KB
assets/base.js (removed)	-12.8 KB
assets/token.server.js (removed)	-9.8 KB
assets/tx.js	-9.7 KB
assets/utils.js	-7.6 KB
assets/validators.js (removed)	-5.9 KB
assets/sha3.js (removed)	-5.5 KB
assets/TxEventDescription.js	-2.3 KB
assets/useWatchBlockNumber.js (removed)	-2.1 KB
assets/tty.js (removed)	-1.8 KB
assets/tokens.server.js (removed)	-1.8 KB
...and 27 more

Compared against main branch (baseline from 2/4/2026, 5:13:51 PM)

[github-actions]

Cloudflare Deployments

App	Environment	Status	Preview
explorer	devnet	[OK] Deployed	View Preview
explorer	mainnet	[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
tokenlist	-	[>>] Skipped	No changes