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_installer_review_notes.py

@@ -43,16 +43,16 @@ def test_help_does_not_create_install_log_or_scratch_dir(tmp_path, monkeypatch)
     )
     assert result.returncode == 0
     assert not list((tmp_path / "state").rglob("install-*.log"))
-    assert not list((tmp_path / "tmp").glob("vocalinux-install.*"))
+    assert not list((tmp_path / "tmp").glob("voculinux-install.*"))
 
 
 def test_scratch_dir_owns_pip_logs_and_model_temps() -> None:
     source = _installer_source()
-    assert 'PIP_LOG_DIR="$VOCALINUX_TMP_DIR/pip"' in source
-    assert 'export TMPDIR="$VOCALINUX_TMP_DIR"' in source
-    assert 'TEMP_FILE="$VOCALINUX_TMP_DIR/tiny.pt"' in source
-    assert 'TEMP_FILE="$VOCALINUX_TMP_DIR/ggml-tiny.bin"' in source
-    assert 'TEMP_ZIP="$VOCALINUX_TMP_DIR/$(basename $SMALL_MODEL_URL)"' in source
+    assert 'PIP_LOG_DIR="$VOCULINUX_TMP_DIR/pip"' in source
+    assert 'export TMPDIR="$VOCULINUX_TMP_DIR"' in source
+    assert 'TEMP_FILE="$VOCULINUX_TMP_DIR/tiny.pt"' in source
+    assert 'TEMP_FILE="$VOCULINUX_TMP_DIR/ggml-tiny.bin"' in source
+    assert 'TEMP_ZIP="$VOCULINUX_TMP_DIR/$(basename $SMALL_MODEL_URL)"' in source
 
 
 def test_system_dep_and_venv_failures_use_structured_exit_codes() -> None:
@@ -67,10 +67,10 @@ def test_system_dep_and_venv_failures_use_structured_exit_codes() -> None:
     bootstrap_failure = source.split("install_pinned_build_tools || {", 1)[1].split("}", 1)[0]
     assert 'exit "$EXIT_NETWORK"' in bootstrap_failure
     assert (
-        'print_error "Failed to install Vocalinux package. Installation cannot continue."' in source
+        'print_error "Failed to install Voculinux package. Installation cannot continue."' in source
     )
     assert 'exit "$EXIT_NETWORK"' in source
-    assert "Could not terminate all Vocalinux processes" in source
+    assert "Could not terminate all Voculinux processes" in source
     assert 'exit "$EXIT_USER_ABORT"' in source