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_value_grounding.py

@@ -7,7 +7,7 @@ aggregate_lsh_multi exposes every column where the value appears, grouped by tab
 so the value-grounding widget can let the reviewer choose which column(s) anchor
 the value.
 """
-from nsp.search import aggregate_lsh_multi
+from tht.search import aggregate_lsh_multi
 
 
 def test_value_in_multiple_columns_returns_all():
@@ -64,7 +64,7 @@ def test_empty_hits_returns_empty():
 def test_value_grounded_decision_type_exists():
     # D14a adds the value_grounded decision type so the gate can record the
     # reviewer's choice of which column(s) anchor a cited value.
-    from nsp.decisions import DecisionType
+    from tht.decisions import DecisionType
     import typing
     args = typing.get_args(DecisionType)
     assert "value_grounded" in args