Initial plugin scaffold: lesson scheduling WordPress plugin

- Custom DB tables for availability slots and lesson bookings
- Instructor (wp-admin) and student (front-end) roles with custom capabilities
- REST API under us-scheduler/v1 for availability CRUD and booking
- [us_booking] and [us_student_login] shortcodes for student front end
- PHPUnit + Brain\Monkey unit test suite (29 tests)
- Gitea Actions CI: lint, PHPStan, tests on PHP 8.1/8.2/8.3, no-debug check
- Feature docs under docs/features/

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

tests/Unit/Model/AvailabilitySlotTest.php

@@ -0,0 +1,68 @@
+<?php
+declare(strict_types=1);
+
+namespace Unsupervised\Schedular\Tests\Unit\Model;
+
+use Unsupervised\Schedular\Model\AvailabilitySlot;
+use Unsupervised\Schedular\Tests\Unit\TestCase;
+
+class AvailabilitySlotTest extends TestCase
+{
+    public function testConstructorAndProperties(): void
+    {
+        $slot = new AvailabilitySlot(
+            instructorId: 5,
+            startDt:      '2026-04-01 09:00:00',
+            endDt:        '2026-04-01 10:00:00',
+            isBooked:     false,
+            id:           42,
+        );
+
+        self::assertSame(5, $slot->instructorId);
+        self::assertSame('2026-04-01 09:00:00', $slot->startDt);
+        self::assertSame('2026-04-01 10:00:00', $slot->endDt);
+        self::assertFalse($slot->isBooked);
+        self::assertSame(42, $slot->id);
+    }
+
+    public function testFromRowMapsCorrectly(): void
+    {
+        $row = (object) [
+            'id'            => '7',
+            'instructor_id' => '3',
+            'start_dt'      => '2026-05-10 14:00:00',
+            'end_dt'        => '2026-05-10 15:00:00',
+            'is_booked'     => '1',
+        ];
+
+        $slot = AvailabilitySlot::fromRow($row);
+
+        self::assertSame(7, $slot->id);
+        self::assertSame(3, $slot->instructorId);
+        self::assertTrue($slot->isBooked);
+    }
+
+    public function testToArrayContainsExpectedKeys(): void
+    {
+        $slot = new AvailabilitySlot(1, '2026-04-01 09:00:00', '2026-04-01 10:00:00', false, 10);
+        $arr  = $slot->toArray();
+
+        self::assertArrayHasKey('id', $arr);
+        self::assertArrayHasKey('instructor_id', $arr);
+        self::assertArrayHasKey('start_dt', $arr);
+        self::assertArrayHasKey('end_dt', $arr);
+        self::assertArrayHasKey('is_booked', $arr);
+    }
+
+    public function testDefaultIsBookedIsFalse(): void
+    {
+        $slot = new AvailabilitySlot(1, '2026-04-01 09:00:00', '2026-04-01 10:00:00');
+        self::assertFalse($slot->isBooked);
+    }
+
+    public function testDefaultIdIsNull(): void
+    {
+        $slot = new AvailabilitySlot(1, '2026-04-01 09:00:00', '2026-04-01 10:00:00');
+        self::assertNull($slot->id);
+    }
+}