Refactor worker to use config, DI, and Quartz scheduling

- Add WorkerSettings class and update appsettings for config-driven setup
- Integrate Quartz.NET for job scheduling (FinalizeDocumentJob, APIEnvelopeJob)
- Refactor Program.cs for DI of services (TempFileManager, PDFBurner, etc.)
- Implement TempFileManager for temp folder management and cleanup
- Rewrite Worker class for config validation, DB check, and lifecycle logging
- Update csproj to include Quartz and EnvelopeGenerator.Jobs references
- Improve maintainability, error handling, and logging throughout

EnvelopeGenerator.WorkerService/appsettings.Development.json

@@ -1,8 +1,30 @@
 {
   "Logging": {
     "LogLevel": {
-      "Default": "Information",
+      "Default": "Debug",
       "Microsoft.Hosting.Lifetime": "Information"
     }
+  },
+  "WorkerSettings": {
+    "ConnectionString": "",
+    "Debug": true,
+    "IntervalMinutes": 1,
+    "PdfBurner": {
+      "IgnoredLabels": [
+        "Date",
+        "Datum",
+        "ZIP",
+        "PLZ",
+        "Place",
+        "Ort",
+        "Position",
+        "Stellung"
+      ],
+      "TopMargin": 0.1,
+      "YOffset": -0.3,
+      "FontName": "Arial",
+      "FontSize": 8,
+      "FontStyle": "Italic"
+    }
   }
 }