feat: devnet3 changes

[ch4r10t33r]

Summary

Add support for configuring attestation committee count and automatic aggregator selection for devnet3.

Key Features

1. Attestation Committee Count Configuration

• Add attestation_committee_count parameter in validator-config.yaml (default: 1)
• Automatically extracted and passed to all clients via --attestation-committee-count flag
• Configurable at the network level in the config section

2. Automatic Aggregator Selection

• Implements 1 aggregator per subnet model
• Random selection by default: Automatically selects one random node as aggregator on startup
• Manual override: Use --aggregator <node_name> flag to specify which node should be the aggregator
• Automatically updates isAggregator flag in validator-config.yaml before starting nodes
• All clients automatically receive --is-aggregator flag when designated as aggregator

3. Enhanced Configuration Management

• isAggregator field added to all validators in both local and ansible configs
• parse-vc.sh extracts and exports both isAggregator and attestationCommitteeCount values
• All 7 client command scripts updated to pass both flags appropriately

[KatyaRyazantseva]

Do we need to add the defined number of committees into the config file? It's mentioned in the specs here.

[ch4r10t33r]

Do we need to add the defined number of committees into the config file? It's mentioned in the specs here.

ATM, the attestation_committee_count is hardcoded in the spec as 1. I had made it configurable in my devnet3 PR. So yes, I think its a good idea to add it to the config file.