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/pyproject.toml

@@ -1,5 +1,5 @@
 [project]
-name = "nsp"
+name = "tht"
 version = "0.1.0"
 description = "ThothII harness — deterministic CLI for the NL→SQL workflow"
 requires-python = ">=3.12"
@@ -18,7 +18,7 @@ dependencies = [
 ]
 
 [project.scripts]
-nsp = "nsp.cli:app"
+tht = "tht.cli:app"
 
 [project.optional-dependencies]
 dev = [
@@ -27,6 +27,9 @@ dev = [
     "ruff>=0.5",
 ]
 
+[tool.setuptools.packages.find]
+include = ["tht*"]
+
 [tool.ruff]
 line-length = 100