Each hanzo-mcp now hosts a ZAP server directly on the lowest free port
from [9999..9995], using a POSIX flock for cross-MCP arbitration. The
browser extension discovers and connects to this server without any
node-side bridge in the critical path.
- New hanzo_tools/browser/zap_server.py: wire format, server, lifecycle,
client registry, leases, cluster-visibility config registry.
- _extension_command tries ZAP first (sub-1ms median round-trip on
loopback), falls back to legacy HTTP bridge on :9224 only when no
ZAP-connected client matches. Pinnable via BROWSER_TRANSPORT.
- New tool actions: list_mcp_instances, claim_browser, release_browser
for sub-agent coordination across multiple parallel MCPs.
- Legacy CDP HTTP bridge no longer auto-starts (opt in with
HANZO_CDP_BRIDGE_ENABLED=1). It remains available for non-ZAP MCP
clients.
Tests: 30 new unit tests cover wire format, port arbitration,
multi-MCP coexistence, lease semantics, and cluster registry.
Bench shows 0.35ms median round-trip on local loopback.
Total tests: 4 baseline -> 35 passing (30 zap_server + 1 bench + 4 imports).
zeekay