Release a Windows-friendly runtime zip (v2.7.12)

The releases carried the wheel and the sdist; the only zip was GitHub's source
archive of the whole repository (tests, CI, tools).  A Windows user just wants
to extract a folder and double-click start.bat.

- scripts/build_release_zip.py builds simtrace-analyser-<version>.zip with a
  single top-level directory: the two Python packages, the PWA runtime files
  (frontend/tests and package.json stay out), the four launchers, the udev
  rule, the READMEs and the screenshot.  The .bat entries are written with
  CRLF line endings (cmd.exe mishandles bare-LF labels/goto), the .sh files
  keep their executable bit; LICENSE is included automatically once the repo
  has one.
- tests/test_release_zip.py pins the archive shape, the exclusions, the sw.js
  PRECACHE drift (every precached asset must travel), the CRLF/LF line endings
  and start.sh's mode.
- the release workflow builds the zip, checks it carries start.bat and the
  PWA, uploads it with the run and attaches it to the release.
- READMEs (EN/RU) and the release-notes template offer the zip as the
  Windows-friendly option; version 2.7.12, PWA cache v94.

Verified: the built zip (34 entries, 658 KB compressed) extracted and started
on Linux serves the same index.html; 553 Python + 80 Node tests.

tests/test_release_zip.py

@@ -0,0 +1,104 @@
+"""Tests for the ready-to-run release zip (scripts/build_release_zip.py)."""
+
+import importlib.util
+import re
+import tempfile
+import unittest
+import zipfile
+from pathlib import Path
+
+from simtrace_analyser.version import __version__
+
+REPO = Path(__file__).resolve().parents[1]
+
+# scripts/ is not a package, so load the builder from its path.
+_spec = importlib.util.spec_from_file_location(
+    'build_release_zip', REPO / 'scripts' / 'build_release_zip.py')
+build_release_zip = importlib.util.module_from_spec(_spec)
+_spec.loader.exec_module(build_release_zip)
+
+
+class TestReleaseZip(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls._tmp = tempfile.TemporaryDirectory()
+        cls.archive = build_release_zip.build_zip(cls._tmp.name)
+        with zipfile.ZipFile(cls.archive) as zf:
+            cls.names = zf.namelist()
+
+    @classmethod
+    def tearDownClass(cls):
+        cls._tmp.cleanup()
+
+    def test_name_and_single_top_level_directory(self):
+        top = 'simtrace-analyser-%s' % __version__
+        self.assertEqual(self.archive.name, top + '.zip')
+        for name in self.names:
+            self.assertTrue(name.startswith(top + '/'),
+                            '%s is outside %s/' % (name, top))
+
+    def test_required_entries(self):
+        top = 'simtrace-analyser-%s' % __version__
+        for rel in (
+                'simtrace_analyser/__main__.py',
+                'simtrace_analyser/version.py',
+                'simtrace2_pysniff/__main__.py',
+                'frontend/index.html',
+                'frontend/sw.js',
+                'frontend/manifest.json',
+                'start.sh',
+                'start.bat',
+                'sniff-start.sh',
+                'sniff-start.bat',
+                '70-simtrace2-pysniff.rules',
+                'README.md'):
+            self.assertIn('%s/%s' % (top, rel), self.names)
+
+    def test_dev_only_entries_are_excluded(self):
+        for name in self.names:
+            self.assertNotIn('/tests/', name)
+            self.assertNotIn('/__pycache__/', name)
+            self.assertNotIn('.pyc', name)
+            self.assertNotIn('/.git', name)
+            self.assertNotIn('/.github/', name)
+        self.assertNotIn(
+            'simtrace-analyser-%s/frontend/package.json' % __version__,
+            self.names)
+        self.assertNotIn(
+            'simtrace-analyser-%s/pyproject.toml' % __version__, self.names)
+
+    def test_precache_files_are_in_the_zip(self):
+        # Drift guard: every asset the service worker precaches must travel
+        # with the PWA, otherwise an offline install fails on a fresh extract.
+        text = (REPO / 'frontend' / 'sw.js').read_text()
+        match = re.search(r'PRECACHE\s*=\s*\[(.*?)\]', text, re.S)
+        self.assertIsNotNone(match, 'no PRECACHE array in frontend/sw.js')
+        assets = re.findall(r"'([^']+)'", match.group(1))
+        self.assertTrue(assets)
+        top = 'simtrace-analyser-%s' % __version__
+        for asset in assets:
+            self.assertIn('%s/frontend/%s' % (top, asset), self.names,
+                          'precached %s is missing from the zip' % asset)
+
+    def test_batch_files_use_crlf(self):
+        with zipfile.ZipFile(self.archive) as zf:
+            bats = [n for n in self.names if n.endswith('.bat')]
+            self.assertTrue(bats)
+            for name in bats:
+                data = zf.read(name)
+                self.assertIn(b'\r\n', data, name)
+                self.assertNotIn(b'\n', data.replace(b'\r\n', b''),
+                                 '%s has a bare LF' % name)
+
+    def test_shell_script_is_lf_and_executable(self):
+        name = 'simtrace-analyser-%s/start.sh' % __version__
+        with zipfile.ZipFile(self.archive) as zf:
+            info = zf.getinfo(name)
+            data = zf.read(name)
+        self.assertNotIn(b'\r\n', data)
+        self.assertTrue(info.external_attr >> 16 & 0o100,
+                        'start.sh lost its executable bit')
+
+
+if __name__ == '__main__':
+    unittest.main()