Never drop an enrolled class from upcoming lessons; delete a guardian's children with them; pin the panel's line spacing

Three fixes from testing the branch.

A group class was only listed when its schedule resolved to exact
datetimes, which needs a class time *and* a duration — both optional on
the offering form, and the schedule note exists precisely so a studio can
write "Tuesdays 4:00pm" instead. A class configured that way vanished
from the list, which is the one thing this feature must never do. So
Offering::sessionStarts() splits "when does it meet" from "how long does
it run" (sessionWindows() is that plus the duration, unchanged), and
SessionSchedule degrades instead of disappearing: dated rows with an open
end when there is no duration, and a single row carrying
Offering::scheduleLabel() when there is no time to derive dates from.
Only a class whose last day has passed drops out.

Deleting a guardian now deletes the children linked to them, releasing
each one's lessons and enrolments first. A child account is login-less
and exists only so the guardian has somebody to book for; without the
guardian nobody can reach it, book for it, or be billed for it, so it was
left stranded on the roster still holding slots. A `handled` set makes
the re-entrant delete_user each child deletion fires a no-op, and stops a
circular link recursing.

The upcoming panel never stated its own line-height, so a theme setting
line-height: 0 above it — the usual icon-font reset — was inherited
straight through. Below 1 that produces both reported symptoms at once:
stacked lines overlap, and the status pill's background is shorter than
the text in it. Pinned at the same id-level specificity as the rest.

Tests: composer test (863), composer lint, composer cs all pass.

Co-Authored-By: Claude Opus 5 <[email protected]>

templates/admin/student-detail.php

@@ -9,8 +9,8 @@ use Unsupervised\Schedular\GroupClass\SessionSchedule;
 
 /**
  * @var \WP_User $student
- * @var list<array{id: int, kind: string, start_dt: string, end_dt: string, offering: string, instructor: string, status: string}> $upcoming Booked lessons and upcoming group-class sessions, soonest first.
- * @var list<array{id: int, kind: string, start_dt: string, end_dt: string, offering: string, instructor: string, status: string}> $past
+ * @var list<array{id: int, kind: string, schedule: string|null, start_dt: string, end_dt: string, offering: string, instructor: string, status: string}> $upcoming Booked lessons and upcoming group-class sessions, soonest first. `schedule` is wording to show instead of a date, for a class with no class time set.
+ * @var list<array{id: int, kind: string, schedule: string|null, start_dt: string, end_dt: string, offering: string, instructor: string, status: string}> $past
  * @var list<array{id: int, offering: string, status: string}> $enrolments
  * @var list<array{policy: string, version: string, context: string, accepted_at: string}> $acceptances
  * @var list<array{question: string, answer: string, required: bool}> $registrationInfo
@@ -53,7 +53,18 @@ $renderLessons = static function (array $rows, bool $withActions = false): void
             <?php foreach ($rows as $row) : ?>
                 <?php $isGroupSession = ($row['kind'] ?? 'lesson') === SessionSchedule::KIND; ?>
                 <tr>
-                    <td><?php echo esc_html($row['start_dt'] !== '' ? (string) mysql2date('M j, Y g:i A', $row['start_dt']) : '—'); ?></td>
+                    <td>
+                        <?php
+                        // A class with no class time set has no clock to put it on,
+                        // so it carries wording ("Tuesdays 4:00pm", or its term
+                        // dates) that stands in for the date entirely.
+                        if (($row['schedule'] ?? null) !== null && $row['schedule'] !== '') {
+                            echo esc_html((string) $row['schedule']);
+                        } else {
+                            echo esc_html($row['start_dt'] !== '' ? (string) mysql2date('M j, Y g:i A', $row['start_dt']) : '—');
+                        }
+                        ?>
+                    </td>
                     <td>
                         <?php echo esc_html($row['offering']); ?>
                         <?php if ($isGroupSession) : ?>