refactor(archimate): delete the unreachable private getVoorzieningenConfig duplicate (#468)

`ArchiMateService::getVoorzieningenConfig()` is `private` and has zero
`$this->` call sites in its own file — the only thing that can reach a private
method. It is not reflected into either: the whole of `lib/` contains exactly
one `ReflectionMethod` call site (`SettingsService:4644`) and it targets
`getAmefConfig`, not this method. It cannot run.

It is also a STALE duplicate. `SettingsService::getVoorzieningenConfig()` is
the live resolver — 13 references across the app — and it ends with
`normalizeVoorzieningenConfig()`, which this copy never had. Anything that had
been wired to the copy would have received un-normalised config.

Removing it removes three of gate-50's seventeen unsafe config reads
(`voorzieningen_register`, `voorzieningen_organisatie_schema`,
`voorzieningen_contactpersoon_schema`) by removing code that cannot execute,
not by moving a guard into the checker's window.

Can-fail proof: restoring the file from origin/development puts gate-50 back to
17; with the deletion it reports 14.

phpcs clean, psalm clean, phpstan clean, phpmd clean against the repo baseline,
unit suite 512 tests green.

Author: rubenvdlinde

lib/Service/ArchiMateService.php

@@ -1694,36 +1694,6 @@ public function getAmefConfig(): array
         }//end try
     }//end getAmefConfig()
 
-    /**
-     * Get Voorzieningen configuration directly from IAppConfig
-     *
-     * @return array The voorzieningen configuration
-     */
-    private function getVoorzieningenConfig(): array
-    {
-        $config  = $this->config->getValueString('softwarecatalog', 'voorzieningen_config', '{}');
-        $decoded = json_decode($config, true);
-
-        if (is_array($decoded) === false) {
-            // Fallback to individual config values for backward compatibility.
-            $decoded = [
-                'register'              => $this->config->getValueString('softwarecatalog', 'voorzieningen_register', ''),
-                'organisatie_schema'    => $this->config->getValueString(
-                    'softwarecatalog',
-                        'voorzieningen_organisatie_schema',
-                        ''
-                ),
-                'contactpersoon_schema' => $this->config->getValueString(
-                    'softwarecatalog',
-                        'voorzieningen_contactpersoon_schema',
-                        ''
-                ),
-            ];
-        }
-
-        return $decoded;
-    }//end getVoorzieningenConfig()
-
     /**
      * Get the current status of ArchiMate operations
      *