feat: add MCP server for the website chatbot over a mirrored TYPO3 content feed

src/ContentFeed/Exception/ContentFeedStoppedException.php

@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\ContentFeed\Exception;
+
+/**
+ * Ends the whole sync run, keeping everything as it is. The next scheduled run tries again.
+ *
+ * Thrown for a manifest that cannot be trusted, three consecutive 5xx responses or
+ * timeouts, and anything else that means TYPO3 is not in a state to be read.
+ */
+class ContentFeedStoppedException extends \RuntimeException
+{
+}

src/ContentFeed/Exception/ContentFeedUnavailableException.php

@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\ContentFeed\Exception;
+
+/**
+ * TYPO3 answered 503: the feed has been switched off on its side.
+ */
+class ContentFeedUnavailableException extends ContentFeedStoppedException
+{
+    public function __construct(public readonly ?\DateTimeImmutable $retryAfter)
+    {
+        parent::__construct('TYPO3 switched the content feed off (503)'.(null !== $retryAfter ? ', retry after '.$retryAfter->format('c') : ''));
+    }
+}

src/ContentFeed/Exception/ContentRequestFailedException.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\ContentFeed\Exception;
+
+/**
+ * One request failed without ending the run. The items it was for keep their stored
+ * version and are retried next run.
+ */
+class ContentRequestFailedException extends \RuntimeException
+{
+}

src/ContentFeed/Exception/PagePhaseEndedException.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\ContentFeed\Exception;
+
+/**
+ * Three slow responses in a row: TYPO3 is under load, so no more pages this run. The rest
+ * of the run (bookkeeping, merging) still completes.
+ */
+class PagePhaseEndedException extends \RuntimeException
+{
+}