Add JSON_THROW_ON_ERROR to json_encode calls for fail-fast behavior

Hardens all json_encode calls in RegionalDataHandler to throw JsonException
on encoding failures instead of silently returning false. This ensures any
encoding issues surface immediately rather than potentially writing invalid
data to calendar and i18n files.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: JohnRDOrazio

src/Handlers/RegionalDataHandler.php

@@ -361,7 +361,7 @@ private function createDiocesanCalendar(ResponseInterface $response): ResponseIn
         );
 
         // Use raw payload for json_encode to preserve schema-compliant structure
-        $calendarData = json_encode($rawPayload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
+        $calendarData = json_encode($rawPayload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_THROW_ON_ERROR);
         if (
             false === file_put_contents(
                 $diocesanCalendarFile,
@@ -447,7 +447,7 @@ private function createNationalCalendar(ResponseInterface $response): ResponseIn
         );
 
         // Use raw payload for json_encode to preserve schema-compliant structure
-        $calendarData = json_encode($rawPayload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
+        $calendarData = json_encode($rawPayload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_THROW_ON_ERROR);
         if (
             false === file_put_contents(
                 $nationalCalendarFile,
@@ -536,7 +536,7 @@ private function createWiderRegionCalendar(ResponseInterface $response): Respons
         );
 
         // Use raw payload for json_encode to preserve schema-compliant structure
-        $calendarData = json_encode($rawPayload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
+        $calendarData = json_encode($rawPayload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_THROW_ON_ERROR);
         if (
             false === file_put_contents(
                 $widerRegionFile,
@@ -654,7 +654,7 @@ private function updateNationalCalendar(ResponseInterface $response): ResponseIn
         }
 
         // Use raw payload for json_encode to preserve schema-compliant structure
-        $calendarData = json_encode($rawPayload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
+        $calendarData = json_encode($rawPayload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_THROW_ON_ERROR);
         if (
             false === file_put_contents(
                 $calendarFile,
@@ -747,7 +747,7 @@ private function updateWiderRegionCalendar(ResponseInterface $response): Respons
         }
 
         // Use raw payload for json_encode to preserve schema-compliant structure
-        $calendarData = json_encode($rawPayload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
+        $calendarData = json_encode($rawPayload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_THROW_ON_ERROR);
         if (
             false === file_put_contents(
                 $widerRegionFile,
@@ -838,7 +838,7 @@ private function updateDiocesanCalendar(ResponseInterface $response): ResponseIn
         }
 
         // Use raw payload for json_encode to preserve schema-compliant structure
-        $calendarData = json_encode($rawPayload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
+        $calendarData = json_encode($rawPayload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_THROW_ON_ERROR);
         if (
             false === file_put_contents(
                 $DiocesanCalendarFile,
@@ -1095,7 +1095,7 @@ private function writeI18nFiles(\stdClass $rawPayload, JsonData $i18nFileEnum, a
             if (
                 false === file_put_contents(
                     $i18nFile,
-                    json_encode($litCalEventsI18n, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE) . PHP_EOL
+                    json_encode($litCalEventsI18n, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_THROW_ON_ERROR) . PHP_EOL
                 )
             ) {
                 throw new ServiceUnavailableException("Failed to write to file {$i18nFile}");
@@ -1155,7 +1155,7 @@ private function updateI18nFiles(
                 );
             }
 
-            $i18nContent = json_encode($i18nData, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
+            $i18nContent = json_encode($i18nData, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_THROW_ON_ERROR);
             if (false === file_put_contents($i18nFile, $i18nContent . PHP_EOL)) {
                 throw new ServiceUnavailableException(
                     "Could not update {$resourceDescription} i18n resource at {$i18nFile}."