feat: seed default AI prompt templates into database

Inserts the five built-in prompts (specs_research, ebay_title,
ebay_description, vision_analyze, json_coding) so they appear in the
admin editor immediately. The service still falls back to hardcoded
defaults if a row is deleted.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

migrations/Version20260519010000.php

@@ -0,0 +1,84 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+final class Version20260519010000 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Seed default AI prompt templates';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $now = (new \DateTimeImmutable())->format('Y-m-d H:i:s');
+
+        $prompts = [
+            'specs_research' => <<<'BODY'
+List all known technical specifications for the {{articleType}}: "{{subject}}".
+Include: processor, RAM, storage variants, display size and resolution, GPU, battery capacity,
+ports, connectivity, weight, dimensions, OS, and any other relevant specs.
+If you know this device, be specific and complete. If it is unknown, say so explicitly.
+BODY,
+
+            'ebay_title' => <<<'BODY'
+Create a concise eBay listing title (max 80 characters) for this {{typeName}}.
+Device: {{deviceLabel}}
+Use the most important specifications. Include condition if not "new".
+Condition: {{condition}}
+{{specsSection}}
+Return ONLY the title text, no quotes, no explanation.
+BODY,
+
+            'ebay_description' => <<<'BODY'
+Create a professional eBay listing description in German for this {{typeName}}.
+Device: {{deviceLabel}}
+Include all available specifications in a clear, structured format.
+Mention the condition: {{condition}}.
+{{conditionNotes}}
+{{specsSection}}
+Use HTML formatting (ul, li, strong tags). Max 2000 characters.
+BODY,
+
+            'vision_analyze' => <<<'BODY'
+Look at this nameplate/label photo of IT hardware.
+Extract the manufacturer (brand), model number/designation, and serial number visible on the label.
+Do not guess or add information not on the label.
+Respond in exactly this format (use empty string if not visible):
+MANUFACTURER: <brand name, e.g. Dell, HP, Lenovo, Medion>
+MODEL: <model number or designation>
+SERIAL: <serial number>
+BODY,
+
+            'json_coding' => <<<'BODY'
+Convert the following hardware specifications to a JSON object.
+The JSON must use these exact keys (UUIDs) and follow the indicated value formats:
+
+{{schema}}
+{{missingHint}}
+Specifications text:
+{{specsText}}
+
+Return ONLY valid JSON. No explanation. No markdown. No extra text.
+JSON:
+BODY,
+        ];
+
+        foreach ($prompts as $key => $body) {
+            $this->addSql(
+                'INSERT INTO app.prompt_templates (id, key, body, updated_at) VALUES (gen_random_uuid(), :key, :body, :now)',
+                ['key' => $key, 'body' => $body, 'now' => $now],
+            );
+        }
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql("DELETE FROM app.prompt_templates WHERE key IN ('specs_research', 'ebay_title', 'ebay_description', 'vision_analyze', 'json_coding')");
+    }
+}