fix: resolve DWH REST api keys from installation-local files at runtime

harness/tht/config.py

@@ -166,11 +166,28 @@ class RestConfig(BaseModel):
     """Accesso al DWH via Supabase/PostgREST. base_url es. https://host/dwh/ ."""
 
     base_url: str
-    api_key: str
+    api_key: str | None = None
+    # Installazione-local file path: il contenuto non entra mai in repo/descriptor/config
+    # renderizzata; viene letto solo a runtime dal processo che esegue il comando.
+    api_key_file: str | None = None
     timeout: int = 30
     connect_timeout: int = 5
     ssl_ca: str | None = None  # path al certificato CA (per server con CA interna)
 
+    @model_validator(mode="after")
+    def resolve_api_key(self) -> "RestConfig":
+        if self.api_key is None and self.api_key_file is not None:
+            path = Path(self.api_key_file)
+            if not path.is_file() or path.is_symlink():
+                raise ValueError("api_key_file is unavailable")
+            value = path.read_text(encoding="utf-8").strip()
+            if not value:
+                raise ValueError("api_key_file is empty")
+            self.api_key = value
+        if self.api_key is None:
+            raise ValueError("api_key or api_key_file is required")
+        return self
+
 
 class DatabaseIdentityConfig(BaseModel):
     database: str