feat(#1722) : add initial wallet height setting to avoid rescanning from genesis

[dimension-drifter]

Problem:
Currently, when a wallet is initialized (/wallet/init) or restored (/wallet/restore), the node wallet re-scans the blockchain from height 0 (genesis). This is unnecessary and inefficient, especially for nodes with long blockchain histories.

Root Cause:
The initWallet and restoreWallet methods call recreateRegistry() which deletes and recreates the wallet registry database. The new registry starts at height 0 (EmptyHistoryHeight). When new blocks arrive after wallet initialization, the wallet attempts to scan from height 1 onwards, effectively rescanning the entire blockchain.

Solution:
Set the wallet registry height to the current blockchain height immediately after recreating the registry during wallet initialization/restoration. This ensures the wallet only scans new blocks going forward, not historical blocks.

Changes
:

• [WalletRegistry.scala]: Added setInitialHeight(height: Int) method to set the wallet height without balance changes
• [ErgoWalletService.scala]: Modified recreateRegistry() to call setInitialHeight() with the current blockchain height (state.fullHeight)

Behavior
:

• Before: Wallet initialized at height 0, rescans all blocks from genesis
• After: Wallet initialized at current blockchain height, only scans new blocks

This is the correct behavior because:

• A newly initialized wallet has no prior transaction history to discover
• A restored wallet should use the /wallet/rescan endpoint if historical transactions need to be recovered
• Users can explicitly call /wallet/rescan with fromHeight: 0 if they want to scan from genesis