Add per-embed lesson-type and section options to the booking block

Three sidebar options on the Lesson Booking block, all mirrored as shortcode
attributes and carried to the front end as data attributes on
#us-booking-app (or as omitted containers):

- Lesson type (lessonTypeId / lesson_type) pins the calendar to a single
  private-lesson type: only the times bookable as it are listed, and it is
  the only type bookable there, auto-selected on the registration form. A
  pinned type that is no longer offered says so instead of showing an empty
  calendar.
- Show the lesson-type filter (showTypeFilter / show_filter) drops the
  "Show Only" control for studios that do not want it.
- Sections (displayMode / show) embeds one half of the page — the booking
  calendar or the student's upcoming lessons — so the two can live on
  different pages. The script skips the work belonging to a missing half:
  no availability or catalog request for an upcoming-only embed, no
  bookings request for a booking-only one. An unrecognised value renders
  the whole page. The editor preview follows the same setting.

Also fixes the expanded filter's first lesson type sharing a line with the
"Lesson type" heading — the choices now sit in their own row beneath it.

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

src/Booking/BookingPage.php

@@ -9,11 +9,30 @@ use Unsupervised\Schedular\Val;
 
 class BookingPage {
 
+	/** Booking calendar and the student's upcoming lessons (the default). */
+	public const MODE_BOTH = 'both';
+
+	/** Booking calendar only — no upcoming-lessons panel. */
+	public const MODE_BOOKING = 'booking';
+
+	/** The student's upcoming lessons only — nothing bookable. */
+	public const MODE_UPCOMING = 'upcoming';
+
 	/**
 	 * Renders the booking shortcode/block output.
 	 *
-	 * @param array<int|string, mixed> $atts Block attributes (`loginPageId`) or
-	 *                                       shortcode attributes (`login_page_id`).
+	 * Supported attributes (block / shortcode form):
+	 * - `loginPageId` / `login_page_id` — where logged-out visitors are sent.
+	 * - `lessonTypeId` / `lesson_type` — a private-lesson offering id that pins
+	 *   the calendar to one lesson type: only the times bookable as that type
+	 *   are listed, and only it can be booked. 0 or absent shows every type.
+	 * - `showTypeFilter` / `show_filter` — whether the "Show Only" lesson-type
+	 *   filter is offered (default true; irrelevant when a type is pinned).
+	 * - `displayMode` / `show` — which halves of the page to embed:
+	 *   {@see self::MODE_BOTH} (default), {@see self::MODE_BOOKING} (calendar
+	 *   only) or {@see self::MODE_UPCOMING} (the student's lessons only).
+	 *
+	 * @param array<int|string, mixed> $atts Block or shortcode attributes.
 	 */
 	public function render( array $atts ): string {
 		if ( ! is_user_logged_in() ) {
@@ -38,11 +57,42 @@ class BookingPage {
 		wp_enqueue_style( 'us-scheduler' );
 		wp_enqueue_script( 'us-scheduler' );
 
+		$lessonTypeId   = absint( Val::int( $atts['lessonTypeId'] ?? $atts['lesson_type'] ?? 0 ) );
+		$showTypeFilter = self::toBool( $atts['showTypeFilter'] ?? $atts['show_filter'] ?? true );
+
+		$mode         = self::mode( $atts['displayMode'] ?? $atts['show'] ?? self::MODE_BOTH );
+		$showBooking  = self::MODE_UPCOMING !== $mode;
+		$showUpcoming = self::MODE_BOOKING !== $mode;
+
 		ob_start();
 		include USC_PLUGIN_DIR . 'templates/frontend/booking-page.php';
 		return (string) ob_get_clean();
 	}
 
+	/**
+	 * Normalises the display-mode attribute; anything unrecognised embeds the
+	 * whole page, so a typo never silently hides half of it.
+	 */
+	private static function mode( mixed $value ): string {
+		$mode = strtolower( trim( Val::string( $value ) ) );
+
+		return in_array( $mode, [ self::MODE_BOOKING, self::MODE_UPCOMING ], true ) ? $mode : self::MODE_BOTH;
+	}
+
+	/**
+	 * Reads a boolean attribute. Block attributes arrive as real booleans,
+	 * shortcode attributes as strings — where the words people actually write
+	 * for "off" ("no", "false", "off") are all truthy to PHP, so they are
+	 * matched explicitly rather than cast.
+	 */
+	private static function toBool( mixed $value ): bool {
+		if ( is_string( $value ) ) {
+			return ! in_array( strtolower( trim( $value ) ), [ '', '0', 'no', 'false', 'off' ], true );
+		}
+
+		return Val::bool( $value );
+	}
+
 	/**
 	 * URL the logged-out prompt sends visitors to: the chosen login page when
 	 * one is configured (and still exists), otherwise the WordPress login