fix: per-profile subprocess HOME isolation (#4426) (#7357)

Isolate system tool configs (git, ssh, gh, npm) per profile by injecting
a per-profile HOME into subprocess environments only.  The Python
process's own os.environ['HOME'] and Path.home() are never modified,
preserving all existing profile infrastructure.

Activation is directory-based: when {HERMES_HOME}/home/ exists on disk,
subprocesses see it as HOME.  The directory is created automatically for:
- Docker: entrypoint.sh bootstraps it inside the persistent volume
- Named profiles: added to _PROFILE_DIRS in profiles.py

Injection points (all three subprocess env builders):
- tools/environments/local.py _make_run_env() — foreground terminal
- tools/environments/local.py _sanitize_subprocess_env() — background procs
- tools/code_execution_tool.py child_env — execute_code sandbox

Single source of truth: hermes_constants.get_subprocess_home()

Closes #4426

docker/entrypoint.sh

@@ -9,7 +9,10 @@ INSTALL_DIR="/opt/hermes"
 # (cache/images, cache/audio, platforms/whatsapp, etc.) are created on
 # demand by the application — don't pre-create them here so new installs
 # get the consolidated layout from get_hermes_dir().
-mkdir -p "$HERMES_HOME"/{cron,sessions,logs,hooks,memories,skills}
+# The "home/" subdirectory is a per-profile HOME for subprocesses (git,
+# ssh, gh, npm …).  Without it those tools write to /root which is
+# ephemeral and shared across profiles.  See issue #4426.
+mkdir -p "$HERMES_HOME"/{cron,sessions,logs,hooks,memories,skills,home}
 
 # .env
 if [ ! -f "$HERMES_HOME/.env" ]; then