Feat: TrustGraph i18n & Documentation Translation Updates (#781)

Native CLI i18n: The TrustGraph CLI has built-in translation support
that dynamically loads language strings. You can test and use
different languages by simply passing the --lang flag (e.g., --lang
es for Spanish, --lang ru for Russian) or by configuring your
environment's LANG variable.

Automated Docs Translations: This PR introduces autonomously
translated Markdown documentation into several target languages,
including Spanish, Swahili, Portuguese, Turkish, Hindi, Hebrew,
Arabic, Simplified Chinese, and Russian.

tests/unit/test_base/test_i18n.py

@@ -0,0 +1,40 @@
+from trustgraph.i18n import get_language_pack, get_translator, normalize_language
+
+
+def test_normalize_language_handles_regions_and_accept_language():
+    assert normalize_language(None) == "en"
+    assert normalize_language("") == "en"
+
+    assert normalize_language("es-ES") == "es"
+    assert normalize_language("pt-BR") == "pt"
+    assert normalize_language("zh") == "zh-cn"
+
+    assert normalize_language("es-ES,es;q=0.9,en;q=0.8") == "es"
+    assert normalize_language("unknown") == "en"
+
+
+def test_language_pack_loads_from_resources():
+    pack = get_language_pack("en")
+    assert isinstance(pack, dict)
+
+    # Key should exist and map to a non-empty string.
+    title = pack.get("cli.verify_system_status.title")
+    assert isinstance(title, str)
+    assert title.strip() != ""
+
+
+def test_translator_formats_placeholders():
+    tr = get_translator("en")
+    out = tr.t(
+        "cli.verify_system_status.checking_attempt",
+        name="Pulsar",
+        attempt=2,
+    )
+
+    assert "Pulsar" in out
+    assert "2" in out
+
+
+def test_translator_falls_back_to_key_for_unknown_keys():
+    tr = get_translator("en")
+    assert tr.t("missing.key") == "missing.key"

tests/unit/test_gateway/test_endpoint_i18n.py

@@ -0,0 +1,75 @@
+"""Tests for Gateway i18n pack endpoint."""
+
+import json
+from unittest.mock import MagicMock
+
+import pytest
+from aiohttp import web
+
+from trustgraph.gateway.endpoint.i18n import I18nPackEndpoint
+
+
+class TestI18nPackEndpoint:
+
+    def test_i18n_endpoint_initialization(self):
+        mock_auth = MagicMock()
+
+        endpoint = I18nPackEndpoint(
+            endpoint_path="/api/v1/i18n/packs/{lang}",
+            auth=mock_auth,
+        )
+
+        assert endpoint.path == "/api/v1/i18n/packs/{lang}"
+        assert endpoint.auth == mock_auth
+        assert endpoint.operation == "service"
+
+    @pytest.mark.asyncio
+    async def test_i18n_endpoint_start_method(self):
+        mock_auth = MagicMock()
+        endpoint = I18nPackEndpoint("/api/v1/i18n/packs/{lang}", mock_auth)
+        await endpoint.start()
+
+    def test_add_routes_registers_get_handler(self):
+        mock_auth = MagicMock()
+        mock_app = MagicMock()
+
+        endpoint = I18nPackEndpoint("/api/v1/i18n/packs/{lang}", mock_auth)
+        endpoint.add_routes(mock_app)
+
+        mock_app.add_routes.assert_called_once()
+        call_args = mock_app.add_routes.call_args[0][0]
+        assert len(call_args) == 1
+
+    @pytest.mark.asyncio
+    async def test_handle_unauthorized_on_invalid_auth_scheme(self):
+        mock_auth = MagicMock()
+        mock_auth.permitted.return_value = True
+
+        endpoint = I18nPackEndpoint("/api/v1/i18n/packs/{lang}", mock_auth)
+
+        request = MagicMock()
+        request.path = "/api/v1/i18n/packs/en"
+        request.headers = {"Authorization": "Token abc"}
+        request.match_info = {"lang": "en"}
+
+        resp = await endpoint.handle(request)
+        assert isinstance(resp, web.HTTPUnauthorized)
+
+    @pytest.mark.asyncio
+    async def test_handle_returns_pack_when_permitted(self):
+        mock_auth = MagicMock()
+        mock_auth.permitted.return_value = True
+
+        endpoint = I18nPackEndpoint("/api/v1/i18n/packs/{lang}", mock_auth)
+
+        request = MagicMock()
+        request.path = "/api/v1/i18n/packs/en"
+        request.headers = {}
+        request.match_info = {"lang": "en"}
+
+        resp = await endpoint.handle(request)
+
+        assert resp.status == 200
+        payload = json.loads(resp.body.decode("utf-8"))
+        assert isinstance(payload, dict)
+        assert "cli.verify_system_status.title" in payload