All agent containers now receive their bridge IP dynamically via DHCP
from the dnsmasq pool instead of a hash-derived static address:
- nix/templates/harness-base.nix: networking.useDHCP = true
- nix/modules/hive-gateway.nix: expand DHCP pool to full usable range
(.2 to .254 on /24) — was last-14-IPs-only
- hive-sh4re/src/priv_proto.rs: remove agent_ip from NetworkIsolation
- hive-c0re/src/lifecycle/mod.rs: drop agent_network_ip + DHCP_POOL_SIZE
- hive-c0re/src/lifecycle/host_config.rs: remove agent_network_ip call
- hive-priv/src/main.rs: LOCAL_ADDRESS= empty (DHCP assigns IP);
HOST_ADDRESS still set so nixos-container installs default route
before the DHCP lease arrives
- nix/dhcp-pool-size: deleted (no longer needed)
The nix/dhcp-pool-size single-source-of-truth file and all associated
Rust/Nix dual-constant plumbing are gone — there is no static map.
bridge_gateway_ip() is retained (still needed for HOST_ADDRESS).
Closes#2363
