operator hit 'coder' and 'test' colliding on the same hashed port —
fnv-1a mod 900 has ~0.1% collision probability per pair and clearly
that's not enough. agent_web_port goes stateful:
- per-agent port persisted to /var/lib/hyperhive/agents/<name>/port
- on first call, look up the file; if absent, hash, then probe
forward through the allocated range skipping any port other
agents already claim, then write the chosen value back
- subsequent calls return the persisted port (sticky)
other agents' ports come from their port file if present, else the
fallback is the hashed value — that handles existing deployments
without forcing a rebuild-all just to migrate. rebuilding the
colliding agent re-runs agent_web_port, sees its peer's implicit
hash port as taken, picks the next free slot, persists.
range exhaustion (very unlikely — 900 slots) logs a warning and
returns the hash; the bind-with-retry on the harness will surface
the failure honestly rather than silently looping.