Add atomic reservation support in Redis for goal alert deduplication with expiration. Update Cron logic and add unit tests for validation.

services/nginx/app/tests/Unit/Redis/RedisAtomicReservationTest.php

@@ -0,0 +1,73 @@
+<?php
+
+app_require('classes/redis.php');
+
+use classes\redis;
+use Predis\Client as PredisClient;
+
+class RedisAtomicReservationTestClient extends PredisClient
+{
+    public array $calls = [];
+
+    public function __construct(private mixed $returnValue)
+    {
+    }
+
+    public function set(...$arguments): mixed
+    {
+        $this->calls[] = $arguments;
+        return $this->returnValue;
+    }
+
+    public function disconnect(): void
+    {
+    }
+}
+
+function redis_test_inject_client(redis $redis, PredisClient $client): void
+{
+    $reflection = new ReflectionClass($redis);
+    $property = $reflection->getProperty('redis');
+    $property->setAccessible(true);
+    $property->setValue($redis, $client);
+}
+
+it('claims a slot atomically with nx and expiration', function (): void {
+    global $REDIS_CONFIG;
+
+    $REDIS_CONFIG = [
+        'host' => 'redis',
+        'database' => 0,
+        'password' => '',
+    ];
+
+    $client = new RedisAtomicReservationTestClient('OK');
+
+    $redis = new redis();
+    redis_test_inject_client($redis, $client);
+
+    expect($redis->set_if_absent_with_expiration('goal_alert_sent:22:2026-03-17', '1', 86400))->toBeTrue();
+    expect($client->calls)->toBe([
+        ['goal_alert_sent:22:2026-03-17', '1', 'EX', 86400, 'NX'],
+    ]);
+});
+
+it('returns false when the slot is already claimed and clamps ttl to one second', function (): void {
+    global $REDIS_CONFIG;
+
+    $REDIS_CONFIG = [
+        'host' => 'redis',
+        'database' => 0,
+        'password' => '',
+    ];
+
+    $client = new RedisAtomicReservationTestClient(null);
+
+    $redis = new redis();
+    redis_test_inject_client($redis, $client);
+
+    expect($redis->set_if_absent_with_expiration('goal_alert_sent:22:2026-03-17', '1', 0))->toBeFalse();
+    expect($client->calls)->toBe([
+        ['goal_alert_sent:22:2026-03-17', '1', 'EX', 1, 'NX'],
+    ]);
+});