feat: create autonomous Nivora package repository

Maintain a validated cross-distribution package catalog.
Automate upstream updates, isolated builds, diagnostics, and direct publication.
Build the official GitHub Desktop sources for Linux with working OAuth.

tests/test_validate_repo.py

@@ -0,0 +1,57 @@
+import importlib.util
+import tempfile
+import unittest
+from pathlib import Path
+
+
+MODULE_PATH = Path(__file__).resolve().parents[1] / "tools/validate_repo.py"
+SPEC = importlib.util.spec_from_file_location("validate_repo", MODULE_PATH)
+assert SPEC and SPEC.loader
+VALIDATOR = importlib.util.module_from_spec(SPEC)
+SPEC.loader.exec_module(VALIDATOR)
+
+
+class ParserTests(unittest.TestCase):
+    def test_scalar_and_array(self):
+        text = "name='demo'\narchitectures=('amd64' 'arm64')\n"
+        self.assertEqual(VALIDATOR.scalar(text, "name"), "demo")
+        self.assertEqual(
+            VALIDATOR.array(text, "architectures"), ["amd64", "arm64"]
+        )
+
+    def test_source_arrays_include_architectures(self):
+        text = "sources=('one')\n\nsources_arm64=(\n 'two'\n)\n"
+        self.assertEqual(
+            VALIDATOR.source_arrays(text),
+            {"sources": ["one"], "sources_arm64": ["two"]},
+        )
+
+    def test_local_source_rejects_traversal(self):
+        self.assertEqual(VALIDATOR.local_source_name("local:///LICENSE"), "LICENSE")
+        self.assertEqual(VALIDATOR.local_source_name("local:///../secret"), "")
+        self.assertIsNone(VALIDATOR.local_source_name("https://example.com/file"))
+
+    def test_markdown_targets(self):
+        text = "[Doc](docs/guide.md) <img src='assets/icon.svg'>"
+        self.assertEqual(
+            VALIDATOR.markdown_targets(text), {"docs/guide.md", "assets/icon.svg"}
+        )
+
+
+class LinkTests(unittest.TestCase):
+    def test_missing_link_is_reported(self):
+        with tempfile.TemporaryDirectory() as directory:
+            path = Path(directory) / "README.md"
+            path.write_text("[missing](no.md)\n", encoding="utf-8")
+            old_root = VALIDATOR.ROOT
+            VALIDATOR.ROOT = Path(directory)
+            try:
+                errors = []
+                VALIDATOR.validate_links(path, errors)
+                self.assertEqual(len(errors), 1)
+            finally:
+                VALIDATOR.ROOT = old_root
+
+
+if __name__ == "__main__":
+    unittest.main()