Enhancement: support separate embedding API key (#14067)

Co-authored-by: Claude Code <noreply@anthropic.com>
Co-authored-by: shamoon <4887959+shamoon@users.noreply.github.com>

src/paperless/migrations/0017_applicationconfiguration_llm_embedding_api_key.py

@@ -0,0 +1,23 @@
+# Generated by Django 5.2.16 on 2026-09-11 09:32
+
+from django.db import migrations
+from django.db import models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("paperless", "0016_alter_applicationconfiguration_ai_enabled"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="applicationconfiguration",
+            name="llm_embedding_api_key",
+            field=models.CharField(
+                blank=True,
+                max_length=1024,
+                null=True,
+                verbose_name="Sets the LLM embedding API key",
+            ),
+        ),
+    ]