Add mainnet VDXF keys for vtimestamp.vrsc:: namespace

Populate MAINNET_VDXF with all 6 mainnet i-addresses
(vtimestamp.vrsc::proof.basic and label keys), enabling
mainnet deployment via PUBLIC_VERUS_NETWORK env var.

Migrate VDXF keys to testidx.vrsctest:: namespace

Switch from testidx.vrsc::timestamp.proof.* to testidx.vrsctest::proof.basic.*
so keys resolve correctly through the VRSCTEST namespace. Rename proofBasic
property to match the new schema hierarchy. Bump to v0.4.0.

Add configurable network with testnet/mainnet switch link

Read network from PUBLIC_VERUS_NETWORK env var instead of hardcoding.
Add network badge in header and switch link in footer for
dual-deployment support (separate Vercel projects per network).

GenericRequest migration for identity updates

Fix Cancel button hover styling in VerusID login flow

Use nav-btn class for consistent hover highlight effect matching
other navigation buttons (Verify, Create, Dashboard).

Initial commit: vtimestamp MVP

Verus blockchain timestamp verification app built with SvelteKit.