fix: profile paths broken in Docker — profiles go to /root/.hermes instead of mounted volume (#7170)

In Docker, HERMES_HOME=/opt/data (set in Dockerfile) and users mount
their .hermes directory to /opt/data. However, profile operations used
Path.home() / '.hermes' which resolves to /root/.hermes in Docker —
an ephemeral container path, not the mounted volume.

This caused:
- Profiles created at /root/.hermes/profiles/ (lost on container recreate)
- active_profile sticky file written to wrong location
- profile list looking at wrong directory

Fix: Add get_default_hermes_root() to hermes_constants.py that detects
Docker/custom deployments (HERMES_HOME outside ~/.hermes) and returns
HERMES_HOME as the root. Also handles Docker profiles correctly
(<root>/profiles/<name> → root is grandparent).

Files changed:
- hermes_constants.py: new get_default_hermes_root()
- hermes_cli/profiles.py: _get_default_hermes_home() delegates to shared fn
- hermes_cli/main.py: _apply_profile_override() + _invalidate_update_cache()
- hermes_cli/gateway.py: _profile_suffix() + _profile_arg()
- Tests: 12 new tests covering Docker scenarios

hermes_cli/profiles.py

@@ -115,16 +115,26 @@ _HERMES_SUBCOMMANDS = frozenset({
 def _get_profiles_root() -> Path:
     """Return the directory where named profiles are stored.
 
-    Always ``~/.hermes/profiles/`` — anchored to the user's home,
-    NOT to the current HERMES_HOME (which may itself be a profile).
-    This ensures ``coder profile list`` can see all profiles.
+    Anchored to the hermes root, NOT to the current HERMES_HOME
+    (which may itself be a profile).  This ensures ``coder profile list``
+    can see all profiles.
+
+    In Docker/custom deployments where HERMES_HOME points outside
+    ``~/.hermes``, profiles live under ``HERMES_HOME/profiles/`` so
+    they persist on the mounted volume.
     """
-    return Path.home() / ".hermes" / "profiles"
+    return _get_default_hermes_home() / "profiles"
 
 
 def _get_default_hermes_home() -> Path:
-    """Return the default (pre-profile) HERMES_HOME path."""
-    return Path.home() / ".hermes"
+    """Return the default (pre-profile) HERMES_HOME path.
+
+    In standard deployments this is ``~/.hermes``.
+    In Docker/custom deployments where HERMES_HOME is outside ``~/.hermes``
+    (e.g. ``/opt/data``), returns HERMES_HOME directly.
+    """
+    from hermes_constants import get_default_hermes_root
+    return get_default_hermes_root()
 
 
 def _get_active_profile_path() -> Path: