Chore: Enable SonarQube scanning (#10904)

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

sonar-project.properties

@@ -0,0 +1,24 @@
+sonar.projectKey=paperless-ngx_paperless-ngx
+sonar.organization=paperless-ngx
+sonar.projectName=Paperless-ngx
+sonar.projectVersion=1.0
+
+# Source and test directories
+sonar.sources=src/,src-ui/
+sonar.test.inclusions=**/test_*.py,**/tests.py,**/*.spec.ts,**/*.test.ts
+
+# Language specific settings
+sonar.python.version=3.10,3.11,3.12,3.13
+
+# Coverage reports
+sonar.python.coverage.reportPaths=merged-backend-coverage.xml
+sonar.javascript.lcov.reportPaths=coverage/lcov.info
+
+# Test execution reports
+sonar.junit.reportPaths=**/junit.xml,**/test-results.xml
+
+# Encoding
+sonar.sourceEncoding=UTF-8
+
+# Exclusions
+sonar.exclusions=**/migrations/**,**/node_modules/**,**/static/**,**/venv/**,**/.venv/**,**/dist/**