fix: harden task3 qdrant compatibility boundaries

harness/tht/cli/vector_cmd.py

@@ -18,7 +18,7 @@ from tht.cli.schema_cmd import (
     physical_path,
 )
 from tht.config import Config, ConfigError
-from tht.ports.vector import VectorWriteRecord
+from tht.ports.vector import SemanticIndexIncompatibleError, VectorWriteRecord
 from tht.vectorstore.store import SyncStats, content_hash
 
 vector_app = typer.Typer(help="Indice semantico Qdrant (derivato, rigenerabile)")
@@ -265,6 +265,12 @@ def index_schema_cmd(
         _vector_cfg_or_error(cfg)
         physical, annotations = _load_schema_artifacts(cfg)
         payload = index_schema_data(cfg, physical=physical, annotations=annotations)
+    except SemanticIndexIncompatibleError:
+        if json_output:
+            typer.echo(json.dumps({"status": "failed", "code": "semantic_index_incompatible"}, sort_keys=True, separators=(",", ":")))
+            raise typer.Exit(code=1) from None
+        typer.secho("ERRORE: indice semantico incompatibile.", fg=typer.colors.RED, err=True)
+        raise typer.Exit(code=1) from None
     except _MachineVectorError as error:
         if json_output:
             typer.echo(json.dumps({"status": "failed", "code": error.code}, sort_keys=True, separators=(",", ":")))