Beads are now a property of prayer steps, not separate steps

Each prayer in the library has an optional default_bead_type (small/large/
crucifix). Standard prayers get sensible defaults: Our Father=large,
Hail Mary=small, Sign of Cross=crucifix, Divine Mercy beads accordingly.

In the sequence, each step card shows a bead selector (—/○/●/✝) so users
can override the default per step. Adding a prayer pre-fills its default.

Bead library icon hints (○●✝) appear on prayer cards in the library.
Modal now includes a Bead selector for creating/editing prayers.

Remove the separate Bead Markers library section — beads live on prayers.
build_slides: prayer steps with bead_type now get a real bead_index so
the ring advances correctly during presentation.

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

includes/build_slides.php

@@ -137,6 +137,7 @@ function build_slides(array $session): array {
                 $leader = ($step['leader_text'] ?: $step['all_text']) ?? '';
             }
 
+            $bead_type = $step['bead_type'] ?? null;
             $slides[] = [
                 'id'         => 'custom_' . $i,
                 'type'       => 'prayer',
@@ -144,8 +145,8 @@ function build_slides(array $session): array {
                 'title'      => $step['name'],
                 'leader'     => $leader,
                 'all'        => $all,
-                'bead'       => null,
-                'bead_index' => null,
+                'bead'       => $bead_type,
+                'bead_index' => $bead_type ? $bead_idx++ : null,
             ];
         }