feat(identity): rename user-visible identity to voculinux with one-time legacy import

The fork takes its own name everywhere a user can see it: binaries
(voculinux, voculinux-gui), desktop entry, autostart, tray, D-Bus
namespace (com.voculinux.Voculinux, no alias for the old name),
config/data/cache dirs, single-instance lock, IBus engine identity,
tray icons, resource prefixes, VOCULINUX_* environment names, and the
update-checker user agent. The internal Python module stays vocalinux
and the distribution metadata keeps the upstream URLs as provenance.

On first run a previous Vocalinux install's config.json, custom
dictionary, and portal restore token are copied once into the new
locations (new config always wins, no merge, no write-back); models
re-resolve through the pinned-checksum download path. An offline
naming-sweep test proves no old-name strings remain on user-visible
surfaces outside the allowlist.

Refs #18

tests/test_dbus_activation.py

@@ -16,7 +16,7 @@ import pytest
 if TYPE_CHECKING:
     from vocalinux.dbus_service import VocalinuxDBusService
 
-# gi is mocked globally by conftest. All vocalinux imports are done lazily
+# gi is mocked globally by conftest. All voculinux imports are done lazily
 # inside the individual tests. Importing them at module level would bind their
 # `gi.repository` references at collection time and clash with test_main.py,
 # which replaces sys.modules["gi"] / sys.modules["gi.repository"] wholesale --
@@ -35,7 +35,7 @@ def test_cli_flag_sends_matching_command(flag, command):
     from vocalinux.main import main
 
     with patch("vocalinux.dbus_service.send_command", return_value=True) as mock_send:
-        with patch.object(sys, "argv", ["vocalinux", flag]):
+        with patch.object(sys, "argv", ["voculinux", flag]):
             with pytest.raises(SystemExit) as exc_info:
                 main()
     assert exc_info.value.code == 0
@@ -47,7 +47,7 @@ def test_cli_flag_exits_nonzero_when_no_instance():
     from vocalinux.main import main
 
     with patch("vocalinux.dbus_service.send_command", return_value=False):
-        with patch.object(sys, "argv", ["vocalinux", "--toggle"]):
+        with patch.object(sys, "argv", ["voculinux", "--toggle"]):
             with pytest.raises(SystemExit) as exc_info:
                 main()
     assert exc_info.value.code == 1
@@ -58,7 +58,7 @@ def test_no_trigger_flag_does_not_dispatch():
     from vocalinux.main import main
 
     # Mock single_instance via sys.modules (not patch("...acquire_lock")) so we
-    # don't import the real module and set it as a vocalinux package attribute,
+    # don't import the real module and set it as a voculinux package attribute,
     # which would defeat patch.dict-based single-instance tests elsewhere.
     mock_single_instance = MagicMock()
     mock_single_instance.acquire_lock.return_value = True
@@ -66,7 +66,7 @@ def test_no_trigger_flag_does_not_dispatch():
         # check_dependencies returns False so main() exits early after dispatch.
         with patch.dict(sys.modules, {"vocalinux.single_instance": mock_single_instance}):
             with patch("vocalinux.main.check_dependencies", return_value=False):
-                with patch.object(sys, "argv", ["vocalinux"]):
+                with patch.object(sys, "argv", ["voculinux"]):
                     with pytest.raises(SystemExit):
                         main()
     mock_send.assert_not_called()
@@ -269,7 +269,7 @@ def test_on_bus_acquired_handles_register_failure():
     # Patch GLib.Error to a real class so both the raise and the `except` clause
     # reference the same type and the GLib.Error branch is exercised.
     with patch.object(dbus_service.GLib, "Error", RuntimeError):
-        service._on_bus_acquired(connection, "com.vocalinux.Vocalinux")
+        service._on_bus_acquired(connection, "com.voculinux.Voculinux")
 
     assert service._registration_id == 0
 
@@ -278,8 +278,8 @@ def test_name_acquired_and_lost_are_safe_to_call():
     """The name-acquired/lost callbacks only log and never raise."""
     service = _make_service()
     connection = MagicMock()
-    service._on_name_acquired(connection, "com.vocalinux.Vocalinux")
-    service._on_name_lost(connection, "com.vocalinux.Vocalinux")
+    service._on_name_acquired(connection, "com.voculinux.Voculinux")
+    service._on_name_lost(connection, "com.voculinux.Voculinux")
 
 
 def test_invoke_swallows_callback_errors():