Let the studio book lessons and record intake collected elsewhere

Two related gaps, closed together because the second is created by the first.

A private lesson could only be booked by the student or their guardian, so a
booking taken over the phone had no way in — where group classes have had "Add
students directly" all along. "Book a lesson for a student" is now a panel on
Scheduler and My Lessons: student, open time, lesson type, with weekly term
reservations and a no-charge option for make-up lessons. The booking core is
extracted to Booking\LessonBooker and shared with POST /bookings, so the two
paths cannot drift on offering rules, slot claiming, or billing.

That leaves a registration with no intake answers and no policy acceptances,
because nobody was at a keyboard to give them — already true of every directly
added group-class student. Ticking the boxes on a student's behalf would be an
audit trail that says something untrue, so instead the answers are collected
another way and recorded afterwards, from a lesson's or an enrolment's detail
page. Every recording must say how it was collected, which is stamped on each
row along with who typed it and shown in a new "How it was given" column: a
policy ticked online and one transcribed from paper must never look alike.

Only staff-made registrations qualify (us_lessons.booked_by,
us_group_enrollments.enrolled_by) — one the student made already holds their
own answers. Only what is still missing can be recorded, re-checked at write
time, so a stale or double-posted form cannot duplicate or overwrite. No IP is
stored for a transcription, and accepted_by stays the student while recorded_by
names the staff member.

Intake is now generic over Registration\IntakeSubject, which Lesson and
Enrollment both implement; LessonDetail became Registration\IntakeAudit and is
shared by both detail views rather than duplicated.

Closes #182

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01QfHt6CyJHz6KkA4RuaS7WK

templates/admin/lessons.php

@@ -13,11 +13,102 @@ if (! defined('ABSPATH')) {
  * @var string $prevWeek
  * @var string $nextWeek
  * @var string $baseUrl
+ * @var string $notice
+ * @var string $error
+ * @var array{students: list<array{id: int, name: string}>, offerings: list<array{id: int, label: string}>, slots: list<array{id: int, label: string, weekly: bool}>} $bookForm
  */
 ?>
 <div class="wrap">
     <h1><?php esc_html_e('Lessons', 'unsupervised-schedular'); ?></h1>
 
+    <?php if ('' !== $notice) : ?>
+        <div class="notice notice-success"><p><?php echo esc_html($notice); ?></p></div>
+    <?php endif; ?>
+
+    <?php if ('' !== $error) : ?>
+        <div class="notice notice-error"><p><?php echo esc_html($error); ?></p></div>
+    <?php endif; ?>
+
+    <details class="usc-book-for-student" style="margin:12px 0;" <?php echo '' !== $error ? 'open' : ''; ?>>
+        <summary style="cursor:pointer; font-weight:600;"><?php esc_html_e('Book a lesson for a student', 'unsupervised-schedular'); ?></summary>
+
+        <?php if (empty($bookForm['students']) || empty($bookForm['slots'])) : ?>
+            <p class="description" style="margin-top:8px;">
+                <?php
+                echo empty($bookForm['students'])
+                    ? esc_html__('There are no students to book for yet.', 'unsupervised-schedular')
+                    : esc_html__('There are no open times in the next eight weeks. Add availability first.', 'unsupervised-schedular');
+                ?>
+            </p>
+        <?php else : ?>
+            <form method="post" style="margin-top:8px;">
+                <?php wp_nonce_field('usc_lesson_action'); ?>
+                <input type="hidden" name="usc_action" value="book_for_student">
+                <p class="description">
+                    <?php esc_html_e('Books on the student\'s behalf, without the intake questions and policy agreements they would answer themselves.', 'unsupervised-schedular'); ?>
+                </p>
+                <table class="form-table" role="presentation">
+                    <tr>
+                        <th scope="row"><label for="usc-book-student"><?php esc_html_e('Student', 'unsupervised-schedular'); ?></label></th>
+                        <td>
+                            <select name="student_id" id="usc-book-student" required>
+                                <option value=""><?php esc_html_e('Choose a student', 'unsupervised-schedular'); ?></option>
+                                <?php foreach ($bookForm['students'] as $student) : ?>
+                                    <option value="<?php echo esc_attr((string) $student['id']); ?>"><?php echo esc_html($student['name']); ?></option>
+                                <?php endforeach; ?>
+                            </select>
+                        </td>
+                    </tr>
+                    <tr>
+                        <th scope="row"><label for="usc-book-slot"><?php esc_html_e('Time', 'unsupervised-schedular'); ?></label></th>
+                        <td>
+                            <select name="slot_id" id="usc-book-slot" required style="max-width:100%;">
+                                <option value=""><?php esc_html_e('Choose an open time', 'unsupervised-schedular'); ?></option>
+                                <?php foreach ($bookForm['slots'] as $slot) : ?>
+                                    <option value="<?php echo esc_attr((string) $slot['id']); ?>"><?php echo esc_html($slot['label']); ?></option>
+                                <?php endforeach; ?>
+                            </select>
+                        </td>
+                    </tr>
+                    <tr>
+                        <th scope="row"><label for="usc-book-offering"><?php esc_html_e('Lesson type', 'unsupervised-schedular'); ?></label></th>
+                        <td>
+                            <select name="offering_id" id="usc-book-offering" style="max-width:100%;">
+                                <option value="0"><?php esc_html_e('Use the time\'s own lesson type', 'unsupervised-schedular'); ?></option>
+                                <?php foreach ($bookForm['offerings'] as $offering) : ?>
+                                    <option value="<?php echo esc_attr((string) $offering['id']); ?>"><?php echo esc_html($offering['label']); ?></option>
+                                <?php endforeach; ?>
+                            </select>
+                            <p class="description"><?php esc_html_e('A time already tied to a lesson type is booked as that type; a general time needs one chosen here.', 'unsupervised-schedular'); ?></p>
+                        </td>
+                    </tr>
+                    <tr>
+                        <th scope="row"><?php esc_html_e('Options', 'unsupervised-schedular'); ?></th>
+                        <td>
+                            <label>
+                                <input type="checkbox" name="recurrence_weekly" value="1">
+                                <?php esc_html_e('Reserve this time weekly for the rest of the term', 'unsupervised-schedular'); ?>
+                            </label>
+                            <p class="description"><?php esc_html_e('Only for a time that repeats weekly. Billed upfront as one payment.', 'unsupervised-schedular'); ?></p>
+                            <label>
+                                <input type="checkbox" name="no_charge" value="1">
+                                <?php esc_html_e('No charge — book it free and confirm it now', 'unsupervised-schedular'); ?>
+                            </label>
+                            <p class="description"><?php esc_html_e('For a make-up or goodwill lesson. Otherwise a pending payment is raised at the lesson type\'s price.', 'unsupervised-schedular'); ?></p>
+                        </td>
+                    </tr>
+                    <tr>
+                        <th scope="row"><label for="usc-book-notes"><?php esc_html_e('Notes', 'unsupervised-schedular'); ?></label></th>
+                        <td><input type="text" name="notes" id="usc-book-notes" class="regular-text" maxlength="500"></td>
+                    </tr>
+                </table>
+                <p>
+                    <button type="submit" class="button button-primary"><?php esc_html_e('Book lesson', 'unsupervised-schedular'); ?></button>
+                </p>
+            </form>
+        <?php endif; ?>
+    </details>
+
     <ul class="subsubsub" style="margin-bottom:12px;">
         <li>
             <a href="<?php echo esc_url($baseUrl); ?>" <?php echo 'week' === $view ? 'class="current"' : ''; ?>><?php esc_html_e('Week', 'unsupervised-schedular'); ?></a> |