vitec_card: flipcard layout + card-back fields; shared-column repair

- layout_variant gains the value "flipcard" (onChange: reload)
- "Card Back" palette in the Layout tab directly below layout_variant:
  back_headline (Text, max 100) and back_text (Textarea, richtext),
  displayCond-gated on the flipcard layout; serialised unconditionally -
  the frontend keys the back face on layout_variant, not on field
  presence (spec 7.7)
- backend preview: flipcard badge + back-headline line
- repair "[ Missing label ]" in the card selects: layout_variant /
  background_variant are columns SHARED with vitec_ctabanner, and the
  index-wise Content Blocks merge dropped four card-only values from
  the base item list. Overrides/tt_content.php now pins the base column
  to the cta-banner lists and hands vitec_card its full lists via
  columnsOverrides (respected by FormEngine and DataHandler; an items
  override can only extend, never shorten - array_replace_recursive)
- spec v1.19 incl. head-matter fix (version table was stuck at 1.17)

Server follow-up: database:updateschema "*.add,*.change" + cache:flush

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

packages/vitec/ContentBlocks/ContentElements/card/config.yaml

@@ -99,6 +99,8 @@ fields:
     type: Select
     renderType: selectSingle
     default: vertical
+    # displayCond of the card-back fields depends on this value
+    onChange: reload
     items:
       - label: Vertical (image top, content below)
         value: vertical
@@ -116,6 +118,27 @@ fields:
         value: feature
       - label: Compact (small card, tight spacing)
         value: compact
+      - label: Flip Card (front / back)
+        value: flipcard
+
+  # Card back - only shown when layout_variant = flipcard. displayCond needs
+  # the storage column (vitec_ vendor prefix); the JSON keys stay the plain
+  # identifiers back_headline / back_text and are emitted on EVERY card
+  # (empty when unset) - the frontend keys the back face on layout_variant.
+  - identifier: card_back
+    type: Palette
+    label: Card Back
+    description: Reverse side of the card. Only used (and only shown) when the layout variant is "Flip Card".
+    fields:
+      - identifier: back_headline
+        type: Text
+        max: 100
+        displayCond: 'FIELD:vitec_layout_variant:=:flipcard'
+      - type: Linebreak
+      - identifier: back_text
+        type: Textarea
+        enableRichtext: true
+        displayCond: 'FIELD:vitec_layout_variant:=:flipcard'
 
   - identifier: background_variant
     type: Select

packages/vitec/ContentBlocks/ContentElements/card/language/labels.xlf

@@ -54,6 +54,19 @@
         <source>If set, the whole card becomes clickable. Overrides individual CTAs visually in the frontend.</source>
       </trans-unit>
 
+      <trans-unit id="back_headline.label">
+        <source>Back Headline</source>
+      </trans-unit>
+      <trans-unit id="back_headline.description">
+        <source>Headline on the reverse side of the card. Only used by the Flip Card layout.</source>
+      </trans-unit>
+      <trans-unit id="back_text.label">
+        <source>Back Text</source>
+      </trans-unit>
+      <trans-unit id="back_text.description">
+        <source>Text on the reverse side of the card. Only used by the Flip Card layout.</source>
+      </trans-unit>
+
       <!-- ============================================================== -->
       <!-- layout_variant                                                  -->
       <!-- ============================================================== -->
@@ -84,6 +97,9 @@
       <trans-unit id="layout_variant.items.compact.label">
         <source>Compact (small card, tight spacing)</source>
       </trans-unit>
+      <trans-unit id="layout_variant.items.flipcard.label">
+        <source>Flip Card (front / back)</source>
+      </trans-unit>
 
       <!-- ============================================================== -->
       <!-- background_variant                                              -->

packages/vitec/ContentBlocks/ContentElements/card/templates/backend-preview.html

@@ -31,6 +31,7 @@
                             <f:case value="icon_card">✦</f:case>
                             <f:case value="feature">⭐</f:case>
                             <f:case value="compact">▫</f:case>
+                            <f:case value="flipcard">🔄</f:case>
                             <f:defaultCase>▢</f:defaultCase>
                         </f:switch>
                     </div>
@@ -65,6 +66,10 @@
             </div>
         </f:if>
 
+        <f:if condition="{data.back_headline}">
+            <div class="vitec-preview__body-text">🔄 Back: {data.back_headline}</div>
+        </f:if>
+
         <div class="vitec-preview__ctas">
             <f:if condition="{data.primary_cta_label}">
                 <span class="vitec-preview__cta-btn">{data.primary_cta_label} →</span>
@@ -90,6 +95,7 @@
                 <f:case value="icon_card">✦ Icon Card</f:case>
                 <f:case value="feature">⭐ Feature</f:case>
                 <f:case value="compact">▫ Compact</f:case>
+                <f:case value="flipcard">🔄 Flip Card</f:case>
                 <f:defaultCase>{data.layout_variant}</f:defaultCase>
             </f:switch>
         </span>