Build modified streamline images

The official image from streamline does not currently work for the arm64
platform. As a temporary measure, the source code and docker build scripts
have been lifted from the official images and are used to build locally.

Some additional modifications are made to reduce overall image size, these
are documented in docker/README.md

docker/streamline-src/vendor/laravel/prompts/src/Output/BufferedConsoleOutput.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace Laravel\Prompts\Output;
+
+class BufferedConsoleOutput extends ConsoleOutput
+{
+    /**
+     * The output buffer.
+     */
+    protected string $buffer = '';
+
+    /**
+     * Empties the buffer and returns its content.
+     */
+    public function fetch(): string
+    {
+        $content = $this->buffer;
+        $this->buffer = '';
+
+        return $content;
+    }
+
+    /**
+     * Return the content of the buffer.
+     */
+    public function content(): string
+    {
+        return $this->buffer;
+    }
+
+    /**
+     * Write to the output buffer.
+     */
+    protected function doWrite(string $message, bool $newline): void
+    {
+        $this->buffer .= $message;
+
+        if ($newline) {
+            $this->buffer .= \PHP_EOL;
+        }
+    }
+
+    /**
+     * Write output directly, bypassing newline capture.
+     */
+    public function writeDirectly(string $message): void
+    {
+        $this->doWrite($message, false);
+    }
+}