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"