test: фаза 4 — тесты extractors, ecosystem, i18n, metrics

- test_nexus.py: extract_pypi/go/npm, dispatch, edge cases (16 тестов)
- test_i18n.py: RU/EN переводы, fallback, форматирование, web UI (10 тестов)
- test_metrics.py: Prometheus endpoint (4 теста)
- test_webhooks.py: _detect_ecosystem (6 тестов), Go/npm webhook fixtures
- conftest.py: sample_nexus_go/npm_webhook fixtures
- Всего: 85 тестов (было 50)

tests/test_nexus.py

@@ -0,0 +1,88 @@
+"""Tests for Nexus package info extractors."""
+
+
+from guarddog_nexus.core.nexus import (
+    extract_go_info,
+    extract_npm_info,
+    extract_package_info,
+    extract_pypi_info,
+)
+
+
+class TestPyPIExtractor:
+    def test_simple(self):
+        assert extract_pypi_info("/packages/requests/2.31.0/requests-2.31.0.tar.gz") == (
+            "requests",
+            "2.31.0",
+        )
+
+    def test_leading_slash(self):
+        assert extract_pypi_info("packages/numpy/1.24.0/numpy-1.24.0.tar.gz") == (
+            "numpy",
+            "1.24.0",
+        )
+
+    def test_non_package(self):
+        assert extract_pypi_info("/some/path") is None
+
+    def test_too_short(self):
+        assert extract_pypi_info("/packages/pkg") is None
+
+
+class TestGoExtractor:
+    def test_simple(self):
+        assert extract_go_info("packages/github.com/gorilla/mux/@v/v1.8.0.zip") == (
+            "github.com/gorilla/mux",
+            "v1.8.0",
+        )
+
+    def test_long_module(self):
+        assert extract_go_info(
+            "/packages/github.com/gin-gonic/gin/@v/v1.9.0.zip"
+        ) == ("github.com/gin-gonic/gin", "v1.9.0")
+
+    def test_no_at_v(self):
+        assert extract_go_info("packages/some/pkg/v1.0.0.zip") is None
+
+    def test_empty(self):
+        assert extract_go_info("") is None
+
+
+class TestNpmExtractor:
+    def test_simple(self):
+        assert extract_npm_info("packages/lodash/-/lodash-4.17.21.tgz") == (
+            "lodash",
+            "4.17.21",
+        )
+
+    def test_scoped_package(self):
+        # Note: scoped packages have a different path in Nexus
+        assert extract_npm_info("packages/@scope/name/-/name-1.0.0.tgz") is None
+
+    def test_not_packages(self):
+        assert extract_npm_info("/other/lodash/-/lodash-4.17.21.tgz") is None
+
+    def test_short_path(self):
+        assert extract_npm_info("packages/lodash") is None
+
+
+class TestDispatchExtractor:
+    def test_pypi(self):
+        assert extract_package_info(
+            "/packages/requests/2.31.0/requests-2.31.0.tar.gz", "pypi"
+        ) == ("requests", "2.31.0")
+
+    def test_go(self):
+        assert extract_package_info(
+            "github.com/gorilla/mux/@v/v1.8.0.zip", "go"
+        ) == ("github.com/gorilla/mux", "v1.8.0")
+
+    def test_npm(self):
+        assert extract_package_info(
+            "packages/lodash/-/lodash-4.17.21.tgz", "npm"
+        ) == ("lodash", "4.17.21")
+
+    def test_unknown_ecosystem(self):
+        assert extract_package_info(
+            "/packages/pkg/1.0/file.tar.gz", "unknown"
+        ) == ("pkg", "1.0")