refactor(workflow): contract shared core (#33)

harness/.pi/extensions/gate/core/reserved-labels.mjs

@@ -0,0 +1,43 @@
+// Etichette riservate del gate HITL e helper di deduplica. Modulo PURO (nessuna
+// dipendenza da pi-tui): condiviso da tht-gate.js e testabile in isolamento con
+//   node --test .pi/extensions/test_reserved_labels.mjs
+// `Altro — specifica…` e le due vie di fuga (torna indietro / esci) vengono
+// SEMPRE aggiunte dal gate alle opzioni in arrivo: se il modello ri-propone uno
+// step con queste etichette gia' presenti, stripReserved evita il duplicato.
+
+export const ALTRO = "Altro — specifica…";
+export const QUIT_LABEL = "Esci da Pi (/quit)";
+export const BACK_LABEL = "Torna indietro (fase precedente)";
+export const CONTROL_LABELS = new Set([QUIT_LABEL, BACK_LABEL]);
+
+// Normalize a label to lowercase ASCII tokens: strip diacritics, turn every run
+// of punctuation/space into a single space, trim. "Altro — specifica…" -> "altro specifica".
+function normalize(label) {
+	return String(label)
+		.normalize("NFD")
+		.replace(/[̀-ͯ]/g, "")
+		.toLowerCase()
+		.replace(/[^a-z0-9]+/g, " ")
+		.trim();
+}
+
+const NORM_QUIT = normalize(QUIT_LABEL);
+const NORM_BACK = normalize(BACK_LABEL);
+
+// true if the label is one the gate adds itself. Robust to the variants models
+// emit ("Altro - specificare", "altro", English "Other — specify"): reserved when
+// the FIRST normalized token is exactly "altro"/"other", or the whole normalized
+// label equals the canonical quit/back labels. First-token match keeps real
+// options like "altrove" out of the reserved set.
+export function isReserved(label) {
+	const n = normalize(label);
+	if (!n) return false;
+	const first = n.split(" ")[0];
+	return first === "altro" || first === "other" || n === NORM_QUIT || n === NORM_BACK;
+}
+
+// removes every reserved entry from a list of labels, preserving order and normal
+// entries. Idempotent.
+export function stripReserved(labels) {
+	return labels.filter((label) => !isReserved(label));
+}