Issue 2: Add Reth + Lighthouse for Ethereum Layer 1

[product-labo]

Description:
Deploy Ethereum full node (execution + consensus) for anchoring and data validation.
Tasks:

Run reth for execution layer.

Run lighthouse for consensus layer.

Connect both through shared JWT secret.

Expose RPC endpoints:

HTTP: localhost:8545

WS: localhost:8546
Deliverable: Working Ethereum L1 node with verified block sync.