feat: migrate to pyproject.toml, add test suites, split CI workflows

- Replace requirements.txt with pyproject.toml for modern Python packaging
- Add unit, integration, lint and security test suites under tests/
- Add utils/export_runtime_requirements.py and utils/check_hadolint_sarif.py
- Split monolithic CI into reusable lint.yml, security.yml and tests.yml
- Refactor ci.yml to orchestrate reusable workflows; publish on semver tag only
- Modernize Dockerfile: pin python:3.12-slim, install via pyproject.toml
- Expand Makefile with lint, security, test and CI targets
- Add test-e2e via act with portfolio container stop/start around run
- Fix navbar_logo_visibility.spec.js: win.fullscreen() → win.enterFullscreen()
- Set use_reloader=False in app.run() to prevent double-start in CI
- Add app/core.* and build artifacts to .gitignore
- Fix apt-get → sudo apt-get in tests.yml e2e job
- Fix pip install --ignore-installed to handle stale act cache

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/unit/test_check_hadolint_sarif.py

@@ -0,0 +1,49 @@
+import json
+import unittest
+from pathlib import Path
+from tempfile import TemporaryDirectory
+
+from utils import check_hadolint_sarif
+
+
+class TestCheckHadolintSarif(unittest.TestCase):
+    def test_main_returns_zero_for_clean_sarif(self):
+        sarif_payload = {
+            "runs": [
+                {
+                    "results": [],
+                }
+            ]
+        }
+
+        with TemporaryDirectory() as temp_dir:
+            sarif_path = Path(temp_dir) / "clean.sarif"
+            sarif_path.write_text(json.dumps(sarif_payload), encoding="utf-8")
+
+            exit_code = check_hadolint_sarif.main([str(sarif_path)])
+
+        self.assertEqual(exit_code, 0)
+
+    def test_main_returns_one_for_warnings_or_errors(self):
+        sarif_payload = {
+            "runs": [
+                {
+                    "results": [
+                        {"level": "warning"},
+                        {"level": "error"},
+                    ],
+                }
+            ]
+        }
+
+        with TemporaryDirectory() as temp_dir:
+            sarif_path = Path(temp_dir) / "warnings.sarif"
+            sarif_path.write_text(json.dumps(sarif_payload), encoding="utf-8")
+
+            exit_code = check_hadolint_sarif.main([str(sarif_path)])
+
+        self.assertEqual(exit_code, 1)
+
+
+if __name__ == "__main__":
+    unittest.main()