fix: harden task2 preprocessing and vector guards

harness/tht/cli/vector_cmd.py

@@ -208,9 +208,10 @@ def index_schema_data(
         cfg = config
     _vector_write_or_error(cfg)
     _vector_cfg_or_error(cfg)
-    phys_file = physical_path(cfg)
-    if not phys_file.exists():
-        raise _MachineVectorError("physical_schema_missing")
+    if physical is None:
+        phys_file = physical_path(cfg)
+        if not phys_file.exists():
+            raise _MachineVectorError("physical_schema_missing")
     import yaml
     from pydantic import ValidationError
 
@@ -259,6 +260,9 @@ def index_schema_cmd(
     else:
         cfg = _load_config_or_exit(config)
     try:
+        # Authorization and configuration are checked before touching any artifacts.
+        _vector_write_or_error(cfg)
+        _vector_cfg_or_error(cfg)
         physical, annotations = _load_schema_artifacts(cfg)
         payload = index_schema_data(cfg, physical=physical, annotations=annotations)
     except _MachineVectorError as error:
@@ -267,10 +271,10 @@ def index_schema_cmd(
             raise typer.Exit(code=1) from None
         _render_index_schema_error(error, cfg)
     except Exception:
-        logger.exception("Schema indexing failed")
         if json_output:
             typer.echo(json.dumps({"status": "failed", "code": "schema_index_failed"}, sort_keys=True, separators=(",", ":")))
             raise typer.Exit(code=1) from None
+        logger.exception("Schema indexing failed")
         typer.secho("ERRORE: impossibile indicizzare lo schema.", fg=typer.colors.RED, err=True)
         raise typer.Exit(code=1) from None
     if json_output: