Success-story migration + new plugins + JSON/UX polish

- Success Stories: full migration from old site (48/48, audited),
  markets n:n, quotation content block, columns content block,
  pretty SEO detail URLs via SuccessStoryPathRewrite middleware,
  list/detail split (list page 4 / story page), detailUrl/backUrl
- New plugins: VITEC Locations (grid/list/map + RTE map text),
  VITEC Customer Logos (color/bw logic, only-show-selected),
  VITEC Card (one plugin for product/story/market/solution
  with reloading FlexForm + custom backend preview renderer)
- Eventlist: layout dropdown (list/grid/teaserbar) in settings
- Hero section CB: Images/Video tabs, background video + overlay
- Product JSON: full category rootline (parents), fixed missing
  ConnectionPool import (all-products crash), category tree map
- Backend preview CSS: container-query responsive (narrow columns)
- Docs: ISO architecture spec, root + extension READMEs

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

packages/vitec/Configuration/FlexForms/Usecase.xml

@@ -8,6 +8,17 @@
                 </sheetTitle>
                 <type>array</type>
                 <el>
+                    <settings.backPid>
+                        <label>Back to List View (page)</label>
+                        <description>Page that holds the Success Story list plugin. Used to build the back link in the JSON output.</description>
+                        <config>
+                            <type>group</type>
+                            <allowed>pages</allowed>
+                            <size>1</size>
+                            <maxitems>1</maxitems>
+                        </config>
+                    </settings.backPid>
+
                     <settings.debug>
                         <label>Allow Debug Output.</label>
                         <config>
@@ -19,20 +30,6 @@
                             </items>
                         </config>
                     </settings.debug>                
-                    <settings.usecase>
-                        <label>
-                            Usecase
-                        </label>
-                        <config>
-                            <type>select</type>
-                            <renderType>selectSingle</renderType>
-                            <foreign_table>tx_vitec_domain_model_usecase</foreign_table>
-                            <foreign_table_where>AND tx_vitec_domain_model_usecase.hidden = 0 AND tx_vitec_domain_model_usecase.deleted = 0 ORDER BY tx_vitec_domain_model_usecase.title</foreign_table_where>
-                            <size>1</size>
-                            <minitems>0</minitems>
-                            <maxitems>1</maxitems>
-                        </config>
-                    </settings.usecase>
                     <settings.layout>
                         <label>
                             Layout