refactor(harness): renaming prodotto tht (Onda -1)

Thoth (tht) è il prodotto, PSD è il cliente. Nessun riferimento al contesto
clinico nel codice.

Rinomine:
- comando+package nsp→tht (dir nsp/→tht/, 46 import, pyproject entry point)
- gate nsp-gate.js→tht-gate.js (+ rewrite token, relayIfNspFails→relayIfThtFails)
- workspace chirone.{example,test}.yaml→tht.{example,test}.yaml (generici)
- env THOTH_→THT_ (19 var) + NSP_ stragglers (NSP_HARNESS_ROOT, NSP_SESSION)
- commenti/docstring chirone/psdwp3/policlinico neutralizzati ('the reference
  implementation', 'the DWH')

Aggiunto [tool.setuptools.packages.find] include=['tht*'] (necessario: l'auto-
discovery rompeva con tht/ + workspaces/ come top-level multipli).

.env operatore aggiornato in-place (prefissi THT_, valori preservati, gitignored).

Verifica: pytest 109 passed, npm test 14 pass, tht phase meta --json OK, zero
residui nsp/THOTH_/NSP_/chirone nel package.

harness/tests/test_mschema_render.py

@@ -5,7 +5,7 @@ ThothAI style, schema-dict for AV-SQL). Pure logic, no I/O.
 """
 from datetime import datetime
 
-from nsp.mschema.models import (
+from tht.mschema.models import (
     Annotations,
     ColumnAnnotation,
     ColumnPhysical,
@@ -13,7 +13,7 @@ from nsp.mschema.models import (
     PhysicalSchema,
     TablePhysical,
 )
-from nsp.mschema.render import to_markdown, to_mschema_text, to_schema_dict
+from tht.mschema.render import to_markdown, to_mschema_text, to_schema_dict
 
 
 def _fake_schema() -> PhysicalSchema:
@@ -84,7 +84,7 @@ def test_to_schema_dict_avsql_shape():
 
 def test_annotations_override_description_in_render():
     schema = _fake_schema()
-    from nsp.mschema.models import TableAnnotation
+    from tht.mschema.models import TableAnnotation
     ann = Annotations(tables={
         "dim_pazienti": TableAnnotation(columns={
             "citta": ColumnAnnotation(description="Comune di residenza"),