test: remove tests that do not test behavior and strengthen weak ones

- Remove tests that only check markup, CSS, static text, wire:key strings,
  framework behavior, copied app logic, or expect(true)
- Replace source-grep and Reflection checks of security fixes with tests
  that run the real code (shell quoting, locked properties, 403 checks,
  webhook fork trust, log redaction, Sentinel token cleanup)
- Assert response bodies and unchanged data on API error paths
- Run the Traefik version job through handle() instead of private methods
- Update stale tests for scheduled task props, the default Postgres image,
  and the disabled transfer link of unvalidated servers

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/Unit/DockerComposeInjectionCompatibilityTest.php

@@ -12,9 +12,7 @@ function composeTemplateFiles(): array
 }
 
 test('every service template passes the Compose injection validator', function (string $file) {
-    validateDockerComposeForInjection(file_get_contents($file));
-
-    expect(true)->toBeTrue();
+    expect(fn () => validateDockerComposeForInjection(file_get_contents($file)))->not->toThrow(Exception::class);
 })->with(composeTemplateFiles());
 
 test('the service template corpus is not empty', function () {
@@ -22,9 +20,7 @@ test('the service template corpus is not empty', function () {
 });
 
 test('realistic application Compose files pass the injection validator', function (string $compose) {
-    validateDockerComposeForInjection($compose);
-
-    expect(true)->toBeTrue();
+    expect(fn () => validateDockerComposeForInjection($compose))->not->toThrow(Exception::class);
 })->with([
     'long syntax volumes, bind mounts and named volumes' => <<<'YAML'
 services: