* feat(server): support configurable hostname for managed OpenCode server spawn
Allow the managed OpenCode server bind hostname to be configured via
OPENCHAMBER_OPENCODE_HOSTNAME environment variable (default: 127.0.0.1).
This enables LAN/Tailscale access without a reverse proxy by setting
the hostname to 0.0.0.0.
Closes#597
* fix: address review feedback — input validation, port probe hostname, security docs
- Add defensive parsing for OPENCHAMBER_OPENCODE_HOSTNAME with trim/empty
check and warning log, matching OPENCODE_HOST validation pattern
- Pass configured hostname to resolveManagedOpenCodePort() so port
availability is probed on the actual bind address, avoiding EADDRINUSE
- Add security note in README docs warning about 0.0.0.0 exposure on
untrusted networks
yslee
ea6d4c4d43