Create CLI pipeline entrypoint with validation and preview

src/taetigkeitsnachweis/validator.py

@@ -266,6 +266,7 @@ def validate_business_rules(
     report_year: int,
     allocation_records: list[AllocationRecord],
     matched_assignments: list[MatchedAssignment],
+    project_root: Path,
 ) -> list[ValidationIssue]:
     issues: list[ValidationIssue] = []
 
@@ -301,7 +302,6 @@ def validate_business_rules(
 
     paths_cfg = config["paths"]
     files_cfg = config["files"]
-    project_root = Path.cwd()
     template_path = (
         project_root
         / paths_cfg["template_dir"]