fix: Gitea Traefik routing and connection pool optimization

- Remove middleware reference from Gitea Traefik labels (caused routing issues)
- Optimize Gitea connection pool settings (MAX_IDLE_CONNS=30, authentication_timeout=180s)
- Add explicit service reference in Traefik labels
- Fix intermittent 504 timeouts by improving PostgreSQL connection handling

Fixes Gitea unreachability via git.michaelschiemer.de

src/Framework/ExceptionHandling/ValueObjects/StackTrace.php

@@ -0,0 +1,118 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Framework\ExceptionHandling\ValueObjects;
+
+use IteratorAggregate;
+use Countable;
+use Throwable;
+
+/**
+ * Stack Trace Collection für strukturierte Stack Trace Darstellung
+ *
+ * Enthält eine Sammlung von StackItems und bietet Formatierungsmethoden
+ * für HTML, Console und JSON-Ausgabe.
+ */
+final readonly class StackTrace implements IteratorAggregate, Countable
+{
+    /**
+     * @param StackItem[] $items
+     */
+    public function __construct(
+        private array $items
+    ) {
+    }
+
+    /**
+     * Erstellt StackTrace aus Throwable
+     */
+    public static function fromThrowable(Throwable $exception): self
+    {
+        $items = [];
+        $trace = $exception->getTrace();
+
+        foreach ($trace as $frame) {
+            $items[] = StackItem::fromArray($frame);
+        }
+
+        return new self($items);
+    }
+
+    /**
+     * Begrenzt Anzahl der Frames
+     */
+    public function limit(int $maxFrames): self
+    {
+        return new self(array_slice($this->items, 0, $maxFrames));
+    }
+
+    /**
+     * Formatiert für HTML-Ausgabe
+     */
+    public function formatForHtml(): string
+    {
+        $lines = [];
+        foreach ($this->items as $index => $item) {
+            $formatted = sprintf(
+                '#%d %s',
+                $index,
+                htmlspecialchars($item->formatForDisplay(), ENT_QUOTES | ENT_HTML5, 'UTF-8')
+            );
+            $lines[] = $formatted;
+        }
+
+        return implode("\n", $lines);
+    }
+
+    /**
+     * Formatiert für Console-Ausgabe
+     */
+    public function formatForConsole(): string
+    {
+        $lines = [];
+        foreach ($this->items as $index => $item) {
+            $lines[] = sprintf(
+                '#%d %s',
+                $index,
+                $item->formatForDisplay()
+            );
+        }
+
+        return implode("\n", $lines);
+    }
+
+    /**
+     * Konvertiert zu Array für JSON-Serialisierung
+     *
+     * @return array<int, array<string, mixed>>
+     */
+    public function toArray(): array
+    {
+        return array_map(
+            fn(StackItem $item) => $item->toArray(),
+            $this->items
+        );
+    }
+
+    /**
+     * Gibt alle StackItems zurück
+     *
+     * @return StackItem[]
+     */
+    public function getItems(): array
+    {
+        return $this->items;
+    }
+
+    public function getIterator(): \Traversable
+    {
+        return new \ArrayIterator($this->items);
+    }
+
+    public function count(): int
+    {
+        return count($this->items);
+    }
+}
+