Part of #5081. Follow-up to the review of #5131.
- Before this PR, claude read CLAUDE_REMOTE_CONTROL_SESSION_NAME_PREFIX
from managed-settings.json in every context. The environment generator
reaches every unit of the container's manager, including `machinectl
shell` (hivectl choom): machined starts it as a transient
container-shell@ unit (systemd 260.5 src/machine/machine.c:980-1004),
and every unit's exec environment starts from the manager environment
the generators fill (src/core/unit.c:5557, src/core/manager.c:3990-4001).
Shells no unit starts do not get it: `nixos-container root-login` / `run`
enter with nsenter + `su -l`, and getty logins go through login(1). So
hive-facts.nix now also exports the generator's output from
/etc/set-environment (environment.extraInit).
- The generator's read loop kept a last line only when it ended in a
newline; it now keeps one without.
- checks.script-test-agent-hive-facts runs the rendered generator and the
shell snippet (under dash and bash's sh) against sample files: both
facts, a planted LD_PRELOAD/PATH line, a last line without a newline,
an empty file and no file.
- identity.rs: hive_name()'s doc names the facts file as the source.
Part of #5081 (slice S0-1a). An agent's closure no longer depends on the
name or domain of the hive that renders it.
- hive-priv writes /etc/hyperhive-hive-facts (HYPERHIVE_HIVE_NAME,
HYPERHIVE_HIVE_DOMAIN) into the container from the same WriteNspawnFlags
call that writes /etc/hyperhive-bridge-dns. hive-c0re passes the values
from its own unit env. hive-priv refuses a value outside [A-Za-z0-9._-].
- A systemd environment generator in the agent (hive-facts.nix) loads the
file into the container manager's environment, so every unit sees it,
as with the systemd.globalEnvironment entries the render used to emit.
It also builds CLAUDE_REMOTE_CONTROL_SESSION_NAME_PREFIX
(<hive>-<agent>), which left claude's managed settings.
- meta.rs stops forwarding HYPERHIVE_HIVE_{NAME,DOMAIN} and stops setting
services.hyperhive.agent.hiveName. The option is removed (both
spellings now fail with a removal message).
- otel.nix drops the agent's hive= resource label. The swarm collector
upserts hive per authenticated receiver (swarm-otel.nix resource/<h>,
on both the metrics and logs pipelines), so stored series keep it.
The otel first hop, otel enable and the dashboard port are still baked;
they are S0-1b.
