fix(tests): sandbox a dev shell whose HERMES_HOME is the Windows platform root, and pin lazy state.db home resolution

The conftest session sandbox only recognised ~/.hermes as "production", so a Windows dev shell
exporting HERMES_HOME=%LOCALAPPDATA%\hermes was honoured as a custom home; every import-time
path capture (tui_gateway.server._hermes_home) then pointed at the live install and the state.db
guard tripped on store-touching tests (#112692). Compare against the same platform-default root the
guard itself uses. Adds the invariant test for the lazy resolve: a HERMES_HOME redirected after
import is honoured while the context-local override is still ignored (#102526).

tests/conftest.py

@@ -77,8 +77,14 @@ def _hermes_home_points_at_production(value: str) -> bool:
     if not value:
         return True
     try:
+        # The platform-default root, not a hardcoded ``~/.hermes``: Windows installs live under
+        # ``%LOCALAPPDATA%\hermes``, and a dev shell exporting that path used to be honored as
+        # "custom", pinning import-time paths (``tui_gateway.server._hermes_home``) to the live
+        # install so the state.db guard tripped on every store-touching test (#112692).
+        from hermes_state_guard import _real_platform_state_root
+
         resolved = Path(value).expanduser().resolve()
-        real_root = (Path.home() / ".hermes").resolve()
+        real_root = _real_platform_state_root() or (Path.home() / ".hermes").resolve()
     except Exception:
         return True
     if resolved == real_root:

tests/tui_gateway/test_launch_db_home_override_race.py

@@ -46,6 +46,23 @@ def test_get_db_first_touch_under_foreign_override_uses_launch_path(launch_db_en
         reset_hermes_home_override(token)
 
 
+def test_get_db_follows_a_process_home_redirected_after_import(monkeypatch, tmp_path):
+    """The launch handle resolves ``HERMES_HOME`` at first use, not at import (#112692): a harness
+    that redirects the env after ``tui_gateway.server`` is imported must not open the import-time
+    home's state.db. Only the context-local override is ignored (#102526), never the process env."""
+    redirected = tmp_path / "redirected"
+    redirected.mkdir()
+    monkeypatch.setattr(server, "_db", None)
+    monkeypatch.setattr(server, "_db_error", None)
+    monkeypatch.setenv("HERMES_HOME", str(redirected))
+    try:
+        db = server._get_db()
+        assert db is not None
+        assert db.db_path.resolve() == (redirected / "state.db").resolve()
+    finally:
+        registry.close_all()
+
+
 def test_insights_get_reads_the_requested_profile_store_not_the_launch_handle(launch_db_env, monkeypatch, tmp_path):
     """``insights.get {profile}`` was ``scoped=True`` then ``_get_db()``: a scoped first touch pinned
     the launch handle to the foreign store. It must count the requested profile's sessions through