Power House v0.3.4

Signed validator registry and dynamic health discovery.

• cryptographically binds validator registrations to Ed25519 identity and derived libp2p peer IDs
• requires active policy admission before a validator affects public totals
• verifies live node identity and system health every 15 seconds
• replaces hardcoded Prometheus targets and validator totals with atomic discovery
• preserves last-known-good discovery when a registry fails verification
• keeps monitoring enrollment separate from consensus membership transitions

All Rust, network, mutation, status, deployment, package, documentation, and browser contracts passed.