fix(explorer): unwrap zero-address root from callTracer trace

[decofe]

Tempo's callTracer wraps the real execution in a system-level CALL to 0x0000000000000000000000000000000000000000. This makes the trace tree show a confusing 0x000...000.call() as the root instead of the actual contract call.

When the root trace targets the zero address and has exactly one child, unwrap it so the trace tree starts at the actual transaction.

Prompted by: Georgios

[github-actions]

Bundle Size Report

Metric	Size	Δ Change
Total	4.2 MB	-606.1 KB (-12.4%)
Gzip	1.2 MB	-101.0 KB (-7.6%)
Brotli	1.0 MB	-80.6 KB (-7.0%)

Chunk changes (>1KB)

Chunk	Change
assets/KeyManager.js (removed)	-477.4 KB
assets/QueryBuilder.js (removed)	-423.4 KB
assets/router.js	-298.3 KB
assets/wagmi.config.js	-283.2 KB
assets/_hash.js	-128.1 KB
assets/BaseTanStackRouterDevtoolsPanel-Bmws3ikM.js (removed)	-99.5 KB
assets/Intro.js (removed)	-66.0 KB
assets/createSsrRpc.js (removed)	-43.8 KB
assets/isAddressEqual.js	-33.5 KB
assets/Hash.js (removed)	-31.0 KB
assets/path.js (removed)	-30.6 KB
assets/FloatingTanStackRouterDevtools-B7vy70jP.js (removed)	-24.4 KB
assets/_layout.js	-22.2 KB
assets/stringify.js (removed)	-19.7 KB
assets/address.js	-14.1 KB
assets/Address.js	-13.1 KB
assets/getAction.js	-13.0 KB
assets/base.js (removed)	-12.8 KB
assets/utils.js	-10.1 KB
assets/token.server.js (removed)	-9.8 KB
...and 41 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
perf	-	[>>] Skipped	No changes
tokenlist	-	[>>] Skipped	No changes