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>

src/Data/Schema.php

@@ -0,0 +1,43 @@
+<?php
+declare(strict_types=1);
+
+namespace Unsupervised\Schedular\Data;
+
+class Schema
+{
+    /**
+     * Returns CREATE TABLE statements for dbDelta.
+     *
+     * @return list<string>
+     */
+    public static function tables(string $prefix, string $charset): array
+    {
+        return [
+            "CREATE TABLE {$prefix}us_availability (
+                id           BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
+                instructor_id BIGINT UNSIGNED NOT NULL,
+                start_dt     DATETIME        NOT NULL,
+                end_dt       DATETIME        NOT NULL,
+                is_booked    TINYINT(1)      NOT NULL DEFAULT 0,
+                created_at   DATETIME        NOT NULL,
+                PRIMARY KEY (id),
+                KEY instructor_id (instructor_id),
+                KEY start_dt (start_dt)
+            ) {$charset};",
+
+            "CREATE TABLE {$prefix}us_lessons (
+                id            BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
+                slot_id       BIGINT UNSIGNED NOT NULL,
+                student_id    BIGINT UNSIGNED NOT NULL,
+                instructor_id BIGINT UNSIGNED NOT NULL,
+                status        VARCHAR(20)     NOT NULL DEFAULT 'pending',
+                notes         TEXT,
+                created_at    DATETIME        NOT NULL,
+                PRIMARY KEY (id),
+                KEY slot_id (slot_id),
+                KEY student_id (student_id),
+                KEY instructor_id (instructor_id)
+            ) {$charset};",
+        ];
+    }
+}