[Agent] Reorder memory and system prompt sections

- Memory content now appears first, followed by system prompt
- Added "# System Prompt" headline separator between sections
- Updated tests to reflect new message ordering

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

Author: OskarStark

src/agent/src/Memory/MemoryInputProcessor.php

@@ -70,13 +70,15 @@ public function processInput(Input $input): void
         }
 
         $systemMessage = $input->messages->getSystemMessage()->content ?? '';
+
+        $combinedMessage = self::MEMORY_PROMPT_MESSAGE.$memory;
         if ('' !== $systemMessage) {
-            $systemMessage .= \PHP_EOL.\PHP_EOL;
+            $combinedMessage .= \PHP_EOL.\PHP_EOL.'# System Prompt'.\PHP_EOL.\PHP_EOL.$systemMessage;
         }
 
         $messages = $input->messages
             ->withoutSystemMessage()
-            ->prepend(Message::forSystem($systemMessage.self::MEMORY_PROMPT_MESSAGE.$memory));
+            ->prepend(Message::forSystem($combinedMessage));
 
         $input->messages = $messages;
     }

src/agent/tests/Memory/MemoryInputProcessorTest.php

@@ -86,15 +86,17 @@ public function testItIsAddingMemoryToSystemPrompt()
         $this->assertArrayNotHasKey('use_memory', $input->getOptions());
         $this->assertSame(
             <<<MARKDOWN
-                You are a helpful and kind assistant.
-
                 # Conversation Memory
                 This is the memory I have found for this conversation. The memory has more weight to answer user input,
                 so try to answer utilizing the memory as much as possible. Your answer must be changed to fit the given
                 memory. If the memory is irrelevant, ignore it. Do not reply to the this section of the prompt and do not
                 reference it as this is just for your reference.
 
                 First memory content
+
+                # System Prompt
+
+                You are a helpful and kind assistant.
                 MARKDOWN,
             $input->messages->getSystemMessage()->content,
         );