feat: implement content cache

Signed-off-by: Sebastian Krupinski <krupinski01@gmail.com>

lib/Providers/MessageProperties.php

@@ -20,12 +20,20 @@ use KTXF\Mail\Object\MessagePropertiesMutableAbstract;
  */
 class MessageProperties extends MessagePropertiesMutableAbstract {
 
+    /**
+     * Part ids of text sections that were cut off when fetched (cache only, not part of the API shape)
+     *
+     * @var list<string>
+     */
+    private array $incompleteSections = [];
+
     /**
      * Convert IMAP data to mail message properties object.
      */
     public function fromImap(Message $message): static
     {
         $this->data[static::PROPERTY_SIZE] = $message->size();
+        $this->incompleteSections = $message->truncatedSections();
 
         if ($message->messageId() !== null) {
             $this->data[static::PROPERTY_URID] = $message->messageId();
@@ -111,6 +119,22 @@ class MessageProperties extends MessagePropertiesMutableAbstract {
 
     // ── Cache (meta store / content store) ───────────────────────────────────
 
+    /**
+     * Part ids of text sections that were cut off when fetched and must be completed on open.
+     *
+     * @return list<string>
+     */
+    public function getIncompleteSections(): array
+    {
+        return $this->incompleteSections;
+    }
+
+    public function setIncompleteSections(string ...$partIds): static
+    {
+        $this->incompleteSections = array_values(array_unique($partIds));
+        return $this;
+    }
+
     /**
      * Serialise the fields the meta store needs for list, filter and sort.
      *