[pedropombeiro]

Root cause of the work-laptop failure

haToken used ${HA_OPENCODE_TOKEN}, and that variable was not in the opencode process environment. resolveHaConfig() returned undefined, so the poll never started. The notification arrived, tapping it did nothing, and the agent stayed blocked.

Reproduced locally, including the 5s backstop clear that identified the plugin as never having consumed the helper:

06:53:38 WEBHOOK waiting reason=question id=que_018cc03b70016m0uKDwckjc6GQ
         que_018cc…: not polling because haToken references HA_OPENCODE_TOKEN,
                     which is not set in the opencode process environment
06:54:22 HA WROTE RESPONSE -> question:que_018cc…:1
06:54:27 HA BACKSTOP CLEARED (plugin was too slow)

The 0.7.2 tracing did its job — it pointed straight at the config — but its message lumped three unrelated causes into one line.

Changes

Name the exact missing variable instead of a generic "config unavailable":

Situation	Message
haApiUrl absent	haApiUrl is not set
haToken absent	haToken is not set
env var unset	haToken references HA_OPENCODE_TOKEN, which is not set in the opencode process environment
several unset	lists all of them
expands to empty	haToken resolved to an empty value

Report partial expansion. ${A}${B} with only B unset previously resolved non-empty, so the plugin silently sent a truncated token that Home Assistant would reject. That now reports …so the token is incomplete while still attempting the poll.

README documents that expansion reads the opencode process environment rather than an interactive shell, that opencode does not read .env files, and that a mise [env] entry does reach the process.

Verification

Two findings established by testing rather than assumption:

• opencode does not read .env — a .env var was invisible to a probe plugin while a shell-exported one was visible.
• mise [env] does reach opencode plugins — verified with the same probe.

Also verified:

• All six config states produce the correct message (unit harness).
• The healthy path is unaffected: reply accepted (HTTP 200).
• The failing path reproduced in a real opencode process at production timing, with the diagnostic appearing in the real log.

mise run typecheck, lint, build all pass.

Note

The user's work machine is already fixed by configuration; no code change was required to unblock it. This PR is about making the next occurrence self-diagnosing.