build(release): several apps released in one run (train:minor learn), their version commits pushed without the checks

The release tool and tool/with_signing_keys.sh take several apps, each with its version
after a colon or none, and release them one after another, each as alone, stopping at
the first that fails; the key script fetches every named app's key.

The pre-push hook skips tool/check.dart when a push brings release commits alone: the
release tool's chore(release) subject, an app's pubspec changed in its version line and
its texts of what's new, nothing else (tool/release_push.dart). Signatures are checked as
before, and CI still runs the checks. A release no longer costs a run of the checks.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

test/release/targets_test.dart

@@ -0,0 +1,47 @@
+import 'package:test/test.dart';
+
+import '../../tool/src/release/targets.dart';
+import '../../tool/src/release/version.dart';
+
+void main() {
+  const apps = {'learn', 'todo', 'train'};
+
+  test('one app, as before, with or without the version asked for', () {
+    expect(parseTargets(['learn'], apps), [const ReleaseTarget('learn')]);
+    expect(parseTargets(['train', 'minor'], apps), [
+      const ReleaseTarget('train', Bump.minor),
+    ]);
+  });
+
+  test('several apps, one after another in the order named, each with its '
+      'own version asked for after a colon or not at all', () {
+    expect(parseTargets(['train:minor', 'learn'], apps), [
+      const ReleaseTarget('train', Bump.minor),
+      const ReleaseTarget('learn'),
+    ]);
+    expect(parseTargets(['learn', 'train', 'patch'], apps), [
+      const ReleaseTarget('learn'),
+      const ReleaseTarget('train', Bump.patch),
+    ]);
+  });
+
+  test('refuses no app, an unknown one, one named twice, a version without '
+      'its app or asked for twice, and an unknown version', () {
+    for (final words in [
+      <String>[],
+      ['meditate'],
+      ['learn', 'learn:minor'],
+      ['minor'],
+      ['learn:minor', 'patch'],
+      ['learn', 'minor', 'patch'],
+      ['learn:huge'],
+      ['learn:'],
+    ]) {
+      expect(
+        () => parseTargets(words, apps),
+        throwsFormatException,
+        reason: '$words',
+      );
+    }
+  });
+}