Add full shell, replaceable Omics adapter and bilingual interaction

Implement approved specification #32 and tickets #33-#37. Keep host authentication server-verified and pin session interaction language. Compile scoped base selectors for browser compatibility and retain full gutters during CSS pruning.

harness/.pi/extensions/gate/__tests__/archive_repair.test.js

@@ -1,6 +1,7 @@
 const test = require("node:test");
 const assert = require("node:assert/strict");
 const { installRepairGate } = require("../memory/repair.js");
+const { gateText } = require("../core/locale.js");
 
 function gate({ answers, fail = false, resume = false }) {
     let tool;
@@ -8,6 +9,8 @@ function gate({ answers, fail = false, resume = false }) {
     const repair = { repair_id: "receipt", choice: null, status: "proposed", can_apply: true,
         saved: false, indexed: false, options: [{ id: "fix", content: { detail: "Correction" } }] };
     installRepairGate({ registerTool: def => { tool = def; } }, {
+        languageFor: () => "en",
+        gateText,
         workflow: { activate() {}, phase: () => ({ id: "F4" }) },
         memory: { execute: (_ctx, args) => {
             calls.push(args);

harness/.pi/extensions/gate/__tests__/builders.test.js

@@ -208,8 +208,8 @@ test("buildArtifactGate derives approve/reject options from action.kind", () =>
     action: { kind: "approve_reject" },
   });
   assert.deepEqual(w.options, [
-    { id: "approve", label: "Salva e procedi", recommended: true },
-    { id: "reject", label: "Rifiuta" },
+    { id: "approve", label: "Save and proceed", label_i18n: "Save and proceed", recommended: true },
+    { id: "reject", label: "Reject", label_i18n: "Reject" },
   ]);
 });
 
@@ -217,7 +217,7 @@ test("buildArtifactGate: confirm -> single approve; view_only -> no options", ()
   const confirm = buildArtifactGate({
     id: "u1", phase: "F1", title: "t", artifact: { kind: "phase", data: {} }, action: { kind: "confirm" },
   });
-  assert.deepEqual(confirm.options, [{ id: "approve", label: "Salva e procedi", recommended: true }]);
+  assert.deepEqual(confirm.options, [{ id: "approve", label: "Save and proceed", label_i18n: "Save and proceed", recommended: true }]);
   const viewOnly = buildArtifactGate({
     id: "u1", phase: "F1", title: "t", artifact: { kind: "phase", data: {} }, action: { kind: "view_only" },
   });

harness/.pi/extensions/gate/__tests__/enrich.test.js

@@ -214,7 +214,7 @@ test("appendLedgerSection appends only the phase's substantive decisions", () =>
   const out = appendLedgerSection(data, decisions, ["concept_clarified", "ambiguity_open"]);
   assert.equal(out.sections.length, 2);
   const ledger = out.sections[1];
-  assert.equal(ledger.title, "Decisioni registrate in questa fase (dal ledger)");
+  assert.equal(ledger.title, "Decisions recorded in this phase (from the ledger)");
   assert.equal(ledger.items.length, 1);
   assert.equal(ledger.items[0].label, "concept_clarified: ablazione");
   assert.equal(ledger.items[0].value, "solo transcatetere");

harness/.pi/extensions/gate/__tests__/gate_confirm_autoclose.test.js

@@ -18,7 +18,9 @@ if (typeof globalThis.require === "undefined") {
 }
 
 const shell = { current: () => "" };
-cp.execFileSync = (file, args, opts) => shell.current(file, args, opts);
+cp.execFileSync = (file, args, opts) => args[1] === "ensure-interaction-language"
+  ? JSON.stringify({ interaction_language: "it", workspace_language: "it" })
+  : shell.current(file, args, opts);
 
 const META = JSON.stringify({
   max_phase: 8,

harness/.pi/extensions/gate/__tests__/gate_confirm_cte_v2.test.js

@@ -23,7 +23,9 @@ if (typeof globalThis.require === "undefined") {
 // swap `activeStub` instead of clobbering the dispatcher. Each test's existing
 // `cp.execFileSync = fn` / restore-in-finally then Just Works.
 let activeStub = cp.execFileSync;
-const dispatcher = (...args) => activeStub(...args);
+const dispatcher = (...args) => args[1]?.[1] === "ensure-interaction-language"
+  ? JSON.stringify({ interaction_language: "it", workspace_language: "it" })
+  : activeStub(...args);
 Object.defineProperty(cp, "execFileSync", {
   configurable: true,
   get: () => dispatcher,

harness/.pi/extensions/gate/__tests__/gate_datamart_choice.test.js

@@ -30,6 +30,8 @@ async function loadGate() {
 function phase8Stub(calls) {
   return (_file, args) => {
     calls.push(args);
+    if (args[0] === "session" && args[1] === "ensure-interaction-language")
+      return JSON.stringify({ interaction_language: "it", workspace_language: "it" });
     if (args[0] === "phase" && args[1] === "meta") {
       return JSON.stringify({
         max_phase: 8,

harness/.pi/extensions/gate/__tests__/gate_interaction_language.test.js

@@ -0,0 +1,104 @@
+const test = require("node:test");
+const assert = require("node:assert/strict");
+const cp = require("node:child_process");
+const { createRequire } = require("node:module");
+const path = require("node:path");
+const { createFakePi } = require("./fake_pi_runtime.js");
+const GATE = path.join(__dirname, "..", "..", "tht-gate.js");
+if (!globalThis.require) globalThis.require = createRequire(GATE);
+let activeStub = cp.execFileSync;
+const dispatcher = (...args) => activeStub(...args);
+Object.defineProperty(cp, "execFileSync", {
+  configurable: true, get: () => dispatcher, set: fn => { activeStub = fn; },
+});
+
+for (const [language, workspaceLanguage, entry, title, yes, no] of [
+  ["en", "it", "/riprendi-sessione s1", "Generate a datamart?", "Yes, generate the datamart", "No, skip the datamart"],
+  ["it", "en", '/nuova-domanda "Pazienti"', "Vuoi generare un datamart?", "Sì, genera il datamart", "No, salta il datamart"],
+  ["fr-FR", "it", "/riprendi-sessione s1", "Generate a datamart?", "Yes, generate the datamart", "No, skip the datamart"],
+]) test(`manifest language ${language} governs every model turn and generated gate chrome`, async () => {
+  const previous = { exec: cp.execFileSync, session: process.env.THT_SESSION,
+    language: process.env.THT_INTERACTION_LANGUAGE, profile: process.env.THT_PROFILE };
+  process.env.THT_SESSION = "s1";
+  process.env.THT_INTERACTION_LANGUAGE = workspaceLanguage; // stale launch hints have no authority
+  process.env.THT_PROFILE = "server";
+  cp.execFileSync = (_file, args) => {
+    if (args[0] === "session" && args[1] === "ensure-interaction-language")
+      return JSON.stringify({ id: "s1", interaction_language: language, workspace_language: workspaceLanguage });
+    if (args[0] === "session" && args[1] === "retrieval-pack") return "Pazienti: età > 65";
+    if (args[0] === "phase" && args[1] === "meta")
+      return JSON.stringify({ max_phase: 8, phases: [{ num: 8, id: "F8", name: "datamart",
+        emits: ["datamart_requested", "datamart_declined"] }] });
+    if (args[0] === "phase" && args[1] === "show") return "Fase corrente: 8\n";
+    return "";
+  };
+  try {
+    const { default: installGate } = await import(GATE);
+    const { pi, ctx, tools } = createFakePi();
+    ctx.cwd = "/nonexistent-language-test";
+    installGate(pi);
+    await pi.emit("input", { text: entry, source: "rpc" });
+    for (let turn = 0; turn < 2; turn++) {
+      const injected = await pi.emit("before_agent_start", { systemPrompt: "BASE" });
+      assert.ok(injected.systemPrompt.includes(`interaction_language=${language}`));
+      assert.ok(injected.systemPrompt.includes(`workspace_language=${workspaceLanguage}`));
+      assert.match(injected.systemPrompt, /reviewer questions, explanations, and choices/);
+    }
+    let widget;
+    ctx.ui.input = async title => {
+      widget = JSON.parse(title);
+      return JSON.stringify({ id: widget.id, choices: ["skip"] });
+    };
+    await tools.get("reviewer_datamart").def.execute("call", { session: "s1" }, null, null, ctx);
+    assert.equal(widget.title, title);
+    assert.equal(widget.title_i18n, "Generate a datamart?");
+    assert.deepEqual(widget.options.map(o => [o.id, o.label]), [
+      ["generate", yes], ["skip", no],
+    ]);
+  } finally {
+    cp.execFileSync = previous.exec;
+    for (const [key, value] of [["THT_SESSION", previous.session],
+      ["THT_INTERACTION_LANGUAGE", previous.language], ["THT_PROFILE", previous.profile]]) {
+      if (value === undefined) delete process.env[key]; else process.env[key] = value;
+    }
+  }
+});
+
+test("an unavailable manifest blocks model startup instead of trusting a launch hint", async () => {
+  const originalExec = cp.execFileSync;
+  const previousSession = process.env.THT_SESSION;
+  process.env.THT_SESSION = "unavailable";
+  cp.execFileSync = () => { throw new Error("storage unavailable"); };
+  try {
+    const { default: installGate } = await import(GATE);
+    const { pi, ctx } = createFakePi();
+    ctx.cwd = "/nonexistent-language-test";
+    installGate(pi);
+    await pi.emit("input", { text: "/riprendi-sessione unavailable", source: "rpc" });
+    await assert.rejects(pi.emit("before_agent_start", { systemPrompt: "BASE" }), /storage unavailable/);
+  } finally {
+    cp.execFileSync = originalExec;
+    if (previousSession === undefined) delete process.env.THT_SESSION;
+    else process.env.THT_SESSION = previousSession;
+  }
+});
+
+test("artifact and join chrome localize while SQL, decisions and generated text remain verbatim", () => {
+  const { buildArtifactGate, buildJoinReviewRequest } = require("../core/builders.js");
+  const artifact = { kind: "sql", data: "SELECT nome FROM pazienti WHERE stato = 'attivo'" };
+  const options = [{ id: "join-1", label: "Collega pazienti", detail: "p.id = v.id" }];
+  for (const [locale, save, reject, next] of [
+    ["en", "Save and proceed", "Reject", "Continue"],
+    ["it", "Salva e procedi", "Rifiuta", "Continua"],
+    ["fr", "Save and proceed", "Reject", "Continue"],
+  ]) {
+    const gate = buildArtifactGate({ id: "u1", phase: "F7", title: "SQL finale",
+      artifact, action: { kind: "approve_reject" }, locale });
+    assert.deepEqual(gate.options.map(o => [o.id, o.label]), [["approve", save], ["reject", reject]]);
+    assert.deepEqual(gate.artifact, artifact);
+    assert.equal(gate.title, "SQL finale");
+    const joins = buildJoinReviewRequest({ id: "u2", phase: "F4", title: "Join", options, locale });
+    assert.equal(joins.confirm_label, next);
+    assert.deepEqual(joins.options, options);
+  }
+});

harness/.pi/extensions/gate/__tests__/gate_join_review.test.js

@@ -36,6 +36,8 @@ const JOIN_OPTIONS = [
 function shellStub(calls, inputs = []) {
   return (_file, args, options = {}) => {
     calls.push(args.join(" "));
+    if (args[0] === "session" && args[1] === "ensure-interaction-language")
+      return JSON.stringify({ interaction_language: "en", workspace_language: "it" });
     if (options.input) inputs.push(options.input);
     if (args[0] === "phase" && args[1] === "meta") {
       return JSON.stringify({ phases: [{ num: 4, id: "F4" }] });

harness/.pi/extensions/gate/__tests__/gate_memory_promote.test.js

@@ -1,6 +1,7 @@
 const test = require("node:test");
 const assert = require("node:assert/strict");
 const { createMemoryGate } = require("../memory/index.js");
+const { gateText } = require("../core/locale.js");
 const { createFakePi } = require("./fake_pi_runtime.js");
 
 function setup({ phase = 8, response, failure = null } = {}) {
@@ -8,6 +9,8 @@ function setup({ phase = 8, response, failure = null } = {}) {
   const calls = [];
   const summary = { summary_id: "summary", items: [{ id: "rule", card: { subject: "Rule" } }] };
   createMemoryGate({
+    languageFor: () => "en",
+    gateText,
     workflow: { activate() {}, phase: () => ({ number: phase, id: "F" + phase }),
       close: () => { calls.push("close"); return "closed"; } },
     memory: { execute: () => JSON.stringify(summary),

harness/.pi/extensions/gate/__tests__/gate_memory_selection.test.js

@@ -1,6 +1,7 @@
 const test = require("node:test");
 const assert = require("node:assert");
 const { createMemoryGate } = require("../memory/index.js");
+const { gateText } = require("../core/locale.js");
 const { buildMultiselectRequest } = require("../core/builders.js");
 const { isReserved } = require("../core/reserved-labels.mjs");
 const { createFakePi } = require("./fake_pi_runtime.js");
@@ -43,7 +44,7 @@ const MEMORY_OPTIONS = [
 ];
 
 
-function setupRecall(choices) {
+function setupRecall(choices, language = "it") {
   const { pi, tools, ctx } = createFakePi();
   const calls = [];
   let descriptor;
@@ -53,6 +54,8 @@ function setupRecall(choices) {
     return JSON.stringify({ id: descriptor.id, choices });
   };
   const memoryGate = createMemoryGate({
+    languageFor: () => language,
+    gateText,
     workflow: {
       activate: () => calls.push(["activate"]),
       phase: () => ({ number: 8, id: "F8" }),
@@ -117,6 +120,19 @@ test("the Memory facade normalizes search hits and applies only the selected F2
   assert.match(result.content[0].text, /1 decisioni.*La fase resta aperta/s);
 });
 
+test("English Memory chrome preserves Italian content and carries UI translation keys", async () => {
+  const { ctx, memoryGate, descriptor } = setupRecall(["first"], "en");
+  await memoryGate.reviewRecall(ctx, {
+    session: "s1", title: "Memory", options: MEMORY_OPTIONS, allow_empty: true, advance: false,
+  }, "F2");
+  assert.equal(descriptor().title, "Select memories to apply to the question");
+  assert.equal(descriptor().confirm_label, "Apply selected memories");
+  assert.equal(descriptor().confirm_label_i18n, "Apply selected memories");
+  assert.equal(descriptor().options[0].label, "Regola paziente attivo");
+  assert.equal(descriptor().options[0].detail, MEMORY_OPTIONS[0].description);
+  assert.equal(descriptor().options[0].label_i18n, undefined);
+});
+
 test("authoritative UUID card identities survive normalization into the reviewer widget", async () => {
   const { ctx, memoryGate, descriptor } = setupRecall(["first"]);
   const id = "mem-11111111-1111-4111-8111-111111111111";

harness/.pi/extensions/gate/__tests__/gate_promote_autoclose.test.js

@@ -26,7 +26,7 @@ case "$1 $2" in
   "phase show") echo "Fase corrente: ${phase}";;
   "phase meta") echo '{"max_phase":8,"phases":[{"num":2,"id":"F2","emits":[]},{"num":8,"id":"F8","emits":[]}]}';;
   "memory summary") echo '{"summary_id":"saved-review","reviewed":true}';;
-  "session show") echo '{"status":"${status}"}';;
+  "session show"|"session ensure-interaction-language") echo '{"id":"s1","status":"${status}","interaction_language":"it","workspace_language":"it"}';;
   *) echo "OK";;
 esac
 `;

harness/.pi/extensions/gate/__tests__/gate_provided_session.test.js

@@ -11,12 +11,14 @@ test("con THT_SESSION il kickoff usa l'id fornito e NON crea la sessione", async
   const bin = path.join(tmp, "bin");
   fs.mkdirSync(bin);
   const tht = path.join(bin, "tht");
-  fs.writeFileSync(tht, "#!/bin/sh\nexit 1\n", { mode: 0o755 });
+  fs.writeFileSync(tht, '#!/bin/sh\nif [ "$2" = "ensure-interaction-language" ]; then\n' +
+    'echo \'{"interaction_language":"it","workspace_language":"it"}\'\nelse\nexit 1\nfi\n', { mode: 0o755 });
   const oldPath = process.env.PATH;
   process.env.PATH = bin + ":" + oldPath;
   process.env.THT_SESSION = "2026-06-27-100000-test";
   try {
     const { pi, ctx } = createFakePi();
+    ctx.cwd = tmp;
     installGate(pi);
     await pi.emit("input", { source: "rpc", text: '/nuova-domanda "x"' });
     const injected = await pi.emit("before_agent_start", { systemPrompt: "" });
@@ -56,7 +58,9 @@ test("con retrieval pack persistito lo inietta senza chiedere tool call ridondan
   fs.writeFileSync(
     tht,
     "#!/bin/sh\n" +
-      "printf \"# Retrieval pack\\n\\nTABELLA_CANDIDATA\\n\"\n",
+      'if [ "$2" = "ensure-interaction-language" ]; then\n' +
+      'echo \'{"interaction_language":"it","workspace_language":"it"}\'\nelse\n' +
+      "printf \"# Retrieval pack\\n\\nTABELLA_CANDIDATA\\n\"\nfi\n",
     { mode: 0o755 },
   );
   const oldPath = process.env.PATH;

harness/.pi/extensions/gate/__tests__/gate_resume_kickoff.test.js

@@ -1,5 +1,15 @@
 const test = require("node:test");
 const assert = require("node:assert");
+const cp = require("node:child_process");
+const { syncBuiltinESMExports } = require("node:module");
+const originalExec = cp.execFileSync;
+cp.execFileSync = (_file, args) => {
+  if (args[0] === "session" && args[1] === "ensure-interaction-language")
+    return JSON.stringify({ interaction_language: "it", workspace_language: "it" });
+  throw new Error("No retrieval pack in this fixture");
+};
+syncBuiltinESMExports();
+test.after(() => { cp.execFileSync = originalExec; syncBuiltinESMExports(); });
 const { createFakePi } = require("./fake_pi_runtime.js");
 const installGate = require("../../tht-gate.js").default ?? require("../../tht-gate.js");
 

harness/.pi/extensions/gate/__tests__/gate_roundtrip.test.js

@@ -21,5 +21,5 @@ test("no-limbo: undefined (cancel) ri-presenta lo stesso widget", async () => {
   const resp = await emitAndWait(ctx, descriptor);
   assert.deepEqual(resp, { id: "u1", choices: ["a"] });
   assert.equal(ctx.uiCalls.length, 2);                    // ri-presentato una volta
-  assert.ok(ctx.notifications.some((n) => /Esc non chiude/.test(n.message)));
+  assert.ok(ctx.notifications.some((n) => /Esc does not close/.test(n.message)));
 });

harness/.pi/extensions/gate/__tests__/gate_workflow_observable_contract.test.js

@@ -10,7 +10,9 @@ const GATE = path.join(__dirname, "..", "..", "tht-gate.js");
 globalThis.require = createRequire(GATE);
 
 const shell = { current: () => "" };
-cp.execFileSync = (file, args, options) => shell.current(file, args, options);
+cp.execFileSync = (file, args, options) => args[1] === "ensure-interaction-language"
+  ? JSON.stringify({ interaction_language: "it", workspace_language: "it" })
+  : shell.current(file, args, options);
 
 const installGate = require(GATE).default ?? require(GATE);
 
@@ -541,7 +543,7 @@ test("F8 warns about pending indexing but preserves the saved review and finaliz
   const { ctx, tools, calls } = await setupGate({ phase: 8, preview: [PROMOTION_CANDIDATE], indexed: false });
   answerReview(ctx, [PROMOTION_CANDIDATE]);
   await tools.get("reviewer_memory_promote").def.execute("pending", { session: "s1" }, null, null, ctx);
-  assert(ctx.notifications.some(({ message, level }) => level === "warning" && message.includes("Memory saved")));
+  assert(ctx.notifications.some(({ message, level }) => level === "warning" && message.includes("Memory salvata")));
   assert(memoryPromotionMutationArgs(calls).some(args => args.includes("memory_summary_reviewed")));
 });
 test("F8 recovers a saved review without asking again or saving cards again", async () => {

harness/.pi/extensions/gate/core/builders.js

@@ -14,6 +14,7 @@
 
 const SCHEMA_VERSION = 1;
 const RESERVED = ["back", "exit", "other"];
+const { gateText } = require("./locale.js");
 
 const VALID_ACTION_KINDS = new Set(["confirm", "approve_reject", "view_only"]);
 const VALID_INFO_LEVELS = new Set(["info", "warning", "error"]);
@@ -38,6 +39,7 @@ function requireArray(value, name, ctx) {
 // highlight as "(consigliato)".
 function buildSelectRequest({
   id, phase, title, options, intro = null, recommended = null,
+  titleI18n,
 }) {
   requireString(title, "title", "select");
   const opts = requireArray(options, "options", "select");
@@ -48,6 +50,7 @@ function buildSelectRequest({
     schema_version: SCHEMA_VERSION,
     widget: "select",
     title,
+    ...(titleI18n ? { title_i18n: titleI18n } : {}),
     intro,
     recommended,
     options: [...opts],
@@ -61,7 +64,7 @@ function buildSelectRequest({
 // `allowEmpty:false` with zero options is a broken widget and throws.
 function buildMultiselectRequest({
   id, phase, title, options, content = null, selected = [], allowEmpty = false,
-  selectionLabel, confirmLabel,
+  selectionLabel, confirmLabel, titleI18n, selectionLabelI18n, confirmLabelI18n,
 }) {
   requireString(title, "title", "multiselect");
   const opts = requireArray(options, "options", "multiselect");
@@ -77,6 +80,7 @@ function buildMultiselectRequest({
     schema_version: SCHEMA_VERSION,
     widget: "multiselect",
     title,
+    ...(titleI18n ? { title_i18n: titleI18n } : {}),
     allow_empty: allowEmpty,
     options: opts.map((option) => ({ ...option, selected: selected.includes(option.id) })),
     selected: [...selected],
@@ -84,13 +88,15 @@ function buildMultiselectRequest({
     reserved: RESERVED,
     ...(selectionLabel ? { selection_label: selectionLabel } : {}),
     ...(confirmLabel ? { confirm_label: confirmLabel } : {}),
+    ...(selectionLabelI18n ? { selection_label_i18n: selectionLabelI18n } : {}),
+    ...(confirmLabelI18n ? { confirm_label_i18n: confirmLabelI18n } : {}),
   };
 }
 
 // Build an `artifact-gate` ui_request: a rendered artifact + a disposition list
 // (confirm / approve_reject / view_only). The decision is load-bearing on the
 // document, so the artifact is never shown alone (spec §4.1).
-function buildArtifactGate({ id, phase, title, artifact, action }) {
+function buildArtifactGate({ id, phase, title, artifact, action, locale = "en" }) {
   requireString(title, "title", "artifact-gate");
   if (!artifact || typeof artifact !== "object") {
     throw new Error("builders: artifact-gate requires an artifact object");
@@ -105,10 +111,10 @@ function buildArtifactGate({ id, phase, title, artifact, action }) {
   }
   const ACTION_OPTIONS = {
     approve_reject: [
-      { id: "approve", label: "Salva e procedi", recommended: true },
-      { id: "reject", label: "Rifiuta" },
+      { id: "approve", label: gateText(locale, "save"), label_i18n: gateText("en", "save"), recommended: true },
+      { id: "reject", label: gateText(locale, "reject"), label_i18n: gateText("en", "reject") },
     ],
-    confirm: [{ id: "approve", label: "Salva e procedi", recommended: true }],
+    confirm: [{ id: "approve", label: gateText(locale, "save"), label_i18n: gateText("en", "save"), recommended: true }],
     view_only: [],
   };
   return {
@@ -180,7 +186,7 @@ function buildSchemaLinkingRequest({ id, phase, title, tables }) {
 // Build a blocking, read-only join review. The reviewer can accept the complete
 // proposal or use Other to request a textual correction; individual joins are
 // deliberately not selectable because omitting one could create a Cartesian product.
-function buildJoinReviewRequest({ id, phase, title, options }) {
+function buildJoinReviewRequest({ id, phase, title, options, locale = "en" }) {
   requireString(title, "title", "join-review");
   const opts = requireArray(options, "options", "join-review");
   if (opts.length === 0) {
@@ -194,7 +200,8 @@ function buildJoinReviewRequest({ id, phase, title, options }) {
     widget: "join-review",
     title,
     options: [...opts],
-    confirm_label: "Continue",
+    confirm_label: gateText(locale, "continue"),
+    confirm_label_i18n: gateText("en", "continue"),
     reserved: RESERVED,
   };
 }

harness/.pi/extensions/gate/core/enrich.js

@@ -156,12 +156,14 @@ function enrichCteResultColumns(payload, planTables, getColumns) {
 // comes from persisted state, not model prose). `decisions` is session-show's ledger
 // dump; `emits` is the phase's substantive decision-type list from workflow.yaml.
 // No matching decisions -> data returned unchanged. Pure: returns a NEW object.
-function appendLedgerSection(data, decisions, emits) {
+function appendLedgerSection(data, decisions, emits, locale = "en") {
+	const { gateText } = require("./locale.js");
 	const emitSet = new Set(emits || []);
 	const rows = (decisions || []).filter((d) => d && emitSet.has(d.type));
 	if (rows.length === 0) return data;
 	const section = {
-		title: "Decisioni registrate in questa fase (dal ledger)",
+		title: gateText(locale, "ledgerTitle"),
+		title_i18n: gateText("en", "ledgerTitle"),
 		items: rows.map((d) => ({
 			label: `${d.type}: ${d.subject}`,
 			value: d.detail || "",

harness/.pi/extensions/gate/core/locale.js

@@ -0,0 +1,41 @@
+// Only deterministic chrome is translated. Model prose and domain payloads are opaque.
+const en = {
+  save: "Save and proceed", reject: "Reject", continue: "Continue",
+  approvalPrompt: "Approve or reject?", chooseApproval: "Choose Save and proceed or Reject.",
+  datamartTitle: "Generate a datamart?", datamartYes: "Yes, generate the datamart",
+  datamartNo: "No, skip the datamart",
+  memoryTitle: "Select memories to apply to the question", memorySelection: "memories to apply",
+  memoryApply: "Apply selected memories", memoryEmpty: "No reusable memories for this question; continuing to the next phase.",
+  memorySummary: "Memory for future questions", archiveRepair: "Resolve archive conflict",
+  repairError: "The correction could not complete. Review the current archive state before retrying.",
+  ledgerTitle: "Decisions recorded in this phase (from the ledger)",
+  escapeHelp: "Esc does not close the gate: use Back / Exit / Other.",
+  inputHelp: "Answer through the gate widgets. To send free text to the model, start the line with '!'.",
+  memoryIndexWarning: "Memory saved. Index update is incomplete; an administrator can retry it in Memory management.",
+  backUsage: "Usage: /torna <session_id> [N]",
+  backInvalid: "Invalid target (current phase {phase}).",
+  decision: "Decision",
+};
+const it = {
+  save: "Salva e procedi", reject: "Rifiuta", continue: "Continua",
+  approvalPrompt: "Approvi o rifiuti?", chooseApproval: "Scegli «Salva e procedi» o «Rifiuta».",
+  datamartTitle: "Vuoi generare un datamart?", datamartYes: "Sì, genera il datamart",
+  datamartNo: "No, salta il datamart",
+  memoryTitle: "Seleziona le memory da applicare alla domanda", memorySelection: "memory da applicare",
+  memoryApply: "Applica le memory selezionate", memoryEmpty: "Nessuna memory riutilizzabile per questa domanda — passo alla fase successiva.",
+  memorySummary: "Memory per le domande future", archiveRepair: "Risolvi il conflitto negli archivi",
+  repairError: "La correzione non è stata completata. Verifica lo stato attuale degli archivi prima di riprovare.",
+  ledgerTitle: "Decisioni registrate in questa fase (dal ledger)",
+  escapeHelp: "Esc non chiude il gate: usa Torna indietro / Esci / Altro dalle opzioni.",
+  inputHelp: "Durante la sessione rispondi con i widget del gate. Per inviare testo libero al modello inizia la riga con '!'.",
+  memoryIndexWarning: "Memory salvata. L'aggiornamento dell'indice è incompleto; un amministratore può riprovarlo da Gestione Memory.",
+  backUsage: "Uso: /torna <session_id> [N]",
+  backInvalid: "Target non valido (fase corrente {phase}).",
+  decision: "Decisione",
+};
+const catalogs = { en, it };
+function gateText(locale, key) {
+  const language = String(locale || "en").toLowerCase().split("-")[0];
+  return catalogs[language]?.[key] ?? en[key];
+}
+module.exports = { gateText };

harness/.pi/extensions/gate/memory/index.js

@@ -1,9 +1,7 @@
 import { Type } from "typebox";
 import { installRepairGate } from "./repair.js";
 
-// Compatibility note: reviewer labels move verbatim from the composition root.
-// Tickets #22 and #23 require observable parity; translating existing chrome is a
-// separate product behavior change rather than part of these extractions.
+// The composition root supplies manifest language; only deterministic chrome is localized.
 
 function normalizedText(value) {
 	return String(value ?? "").trim().replace(/\s+/g, " ").toLowerCase();
@@ -31,7 +29,7 @@ function memoryOptionKey(option) {
 }
 
 
-function normalizeMemoryOptions(options) {
+function normalizeMemoryOptions(options, locale, gateText) {
 	const seen = new Set();
 	const out = [];
 	for (const option of options) {
@@ -47,7 +45,7 @@ function normalizeMemoryOptions(options) {
 		].join(" ").match(MEMORY_ID_RE)?.[0]?.toLowerCase();
 		const fallbackDetail = [
 			option.decision?.type && option.decision?.subject
-				? `Decisione ${option.decision.type}: ${option.decision.subject}`
+				? `${gateText(locale, "decision")} ${option.decision.type}: ${option.decision.subject}`
 				: "",
 			option.decision?.detail ?? "",
 		].filter(Boolean).join("\n");
@@ -62,12 +60,15 @@ function normalizeMemoryOptions(options) {
 }
 
 
-function memorySelectionWidgetProps(options) {
+function memorySelectionWidgetProps(options, locale, gateText) {
 	return {
-		title: "Seleziona le memory da applicare alla domanda",
+		title: gateText(locale, "memoryTitle"),
+		titleI18n: gateText("en", "memoryTitle"),
 		selected: options.filter((option) => option.recommended).map((option) => option.id),
-		selectionLabel: "memory da applicare",
-		confirmLabel: "Applica le memory selezionate",
+		selectionLabel: gateText(locale, "memorySelection"),
+		confirmLabel: gateText(locale, "memoryApply"),
+		selectionLabelI18n: gateText("en", "memorySelection"),
+		confirmLabelI18n: gateText("en", "memoryApply"),
 	};
 }
 
@@ -78,10 +79,11 @@ function shouldSkipEmptyRecall({ meritCount, allowEmpty, advance }) {
 
 
 async function reviewRecall(ctx, params, phase, dependencies) {
-	const { workflow, ledger, reviewer, waitForReviewer, toTextResult } = dependencies;
+	const { workflow, ledger, reviewer, waitForReviewer, toTextResult, languageFor, gateText } = dependencies;
 	try {
 		const { session, advance } = params;
-		const options = normalizeMemoryOptions(params.options);
+		const locale = languageFor(ctx, session);
+		const options = normalizeMemoryOptions(params.options, locale, gateText);
 		const typeError = ledger.validate(ctx, options, session);
 		if (typeError) return toTextResult(typeError);
 		const meritOptions = options
@@ -99,7 +101,7 @@ async function reviewRecall(ctx, params, phase, dependencies) {
 			advance,
 		})) {
 			await ctx.ui.notify(
-				"Nessuna memory riutilizzabile per questa domanda — passo alla fase successiva.",
+				gateText(locale, "memoryEmpty"),
 				"info",
 			);
 			workflow.advance(ctx, session);
@@ -113,7 +115,7 @@ async function reviewRecall(ctx, params, phase, dependencies) {
 			phase,
 			allowEmpty: params.allow_empty ?? false,
 			options: meritOptions,
-			...memorySelectionWidgetProps(options),
+			...memorySelectionWidgetProps(options, locale, gateText),
 		});
 		const response = await waitForReviewer(ctx, widget);
 		if (response.control === "freetext") {
@@ -161,7 +163,7 @@ async function reviewRecall(ctx, params, phase, dependencies) {
 }
 
 
-function installMemoryGate(pi, { workflow, memory, ledger, waitForReviewer, toTextResult }) {
+function installMemoryGate(pi, { workflow, memory, ledger, waitForReviewer, toTextResult, languageFor, gateText }) {
     pi.registerTool({
         name: "reviewer_memory_promote",
         label: "Review Memory summary",
@@ -188,7 +190,8 @@ function installMemoryGate(pi, { workflow, memory, ledger, waitForReviewer, toTe
                 }
                 const response = await waitForReviewer(ctx, {
                     id: `u${Date.now()}`, schema_version: 1, phase: phase.id,
-                    widget: "memory-review", title: "Memory for future questions",
+                    widget: "memory-review", title: gateText(languageFor(ctx, session), "memorySummary"),
+                    title_i18n: gateText("en", "memorySummary"),
                     summary, reserved: ["other", "back", "exit"],
                 });
                 if (response.control) return toTextResult(

harness/.pi/extensions/gate/memory/repair.js

@@ -1,6 +1,6 @@
 import { Type } from "typebox";
 
-export function installRepairGate(pi, { workflow, memory, waitForReviewer, toTextResult }) {
+export function installRepairGate(pi, { workflow, memory, waitForReviewer, toTextResult, languageFor, gateText }) {
     pi.registerTool({
         name: "reviewer_archive_repair",
         label: "Resolve Memory / Evidence conflict",
@@ -26,6 +26,7 @@ export function installRepairGate(pi, { workflow, memory, waitForReviewer, toTex
             try {
                 if (!!params.repair_id === !!params.proposal)
                     return toTextResult("Supply either a new proposal or an existing repair_id.");
+                const locale = languageFor(ctx, params.session);
                 const run = args => JSON.parse(memory.execute(ctx,
                     [...args, "--session", params.session, "--json"]));
                 let repair = params.repair_id
@@ -36,7 +37,9 @@ export function installRepairGate(pi, { workflow, memory, waitForReviewer, toTex
                     const response = await waitForReviewer(ctx, {
                         id: `u${Date.now()}`, schema_version: 1,
                         phase: workflow.phase(ctx, params.session).id,
-                        widget: "archive-repair", title: "Resolve archive conflict",
+                        widget: "archive-repair", title: gateText(locale, "archiveRepair"),
+                        title_i18n: gateText("en", "archiveRepair"),
+                        ...(error ? { error_i18n: gateText("en", "repairError") } : {}),
                         repair, error, reserved: ["other", "back", "exit"],
                     });
                     if (response.control) return toTextResult(response.control === "freetext"
@@ -62,7 +65,7 @@ export function installRepairGate(pi, { workflow, memory, waitForReviewer, toTex
                             return toTextResult("All repair proposals were rejected as inadequate. " +
                                 "No archive was changed. Reformulate the options for the reviewer.");
                     } catch (failure) {
-                        error = "The correction could not complete. Review the current archive state before retrying.";
+                        error = gateText(locale, "repairError");
                         repair = run(["repair-show", "--repair-id", repair.repair_id]);
                     }
                 }

harness/.pi/extensions/tht-gate.js

@@ -23,6 +23,7 @@
 
 import { execFileSync } from "node:child_process";
 import { readFileSync } from "node:fs";
+import { join } from "node:path";
 import { Type } from "typebox";
 import {
 	buildSelectRequest,
@@ -51,6 +52,7 @@ import {
 	NEW_SESSION_CLARIFICATION_KICKOFF,
 } from "./gate/disambiguation/index.js";
 import { isReserved } from "./gate/core/reserved-labels.mjs";
+import { gateText } from "./gate/core/locale.js";
 
 // Machine-readable RPC notification consumed by SessionBridge. Pi's extension API
 // exposes notify/input but no custom client-event emitter, so this reserved prefix is
@@ -190,6 +192,8 @@ const NUOVA_DOMANDA_KICKOFF =
 	"orchestri, il reviewer decide, la CLI `tht` persiste; NON sei in modalita' autonoma).\n" +
 	'1. Esegui `tht session new "<la domanda dell\'utente nel messaggio sopra>"` e annota ' +
 	"l'id stampato nell'ultima riga.\n" +
+	"Leggi subito `tht session show <id> --json`: usa interaction_language del manifest " +
+	"per ogni domanda, spiegazione e scelta al reviewer, prima della prima interazione.\n" +
 	"2. Segui il workflow dalla Fase 1 (Chiarimento), usando l'id di sessione in ogni " +
 	"comando `tht`.\n" +
 	"Regole non negoziabili (valgono SEMPRE, anche senza la skill):\n" +
@@ -249,11 +253,9 @@ function textResult(text) {
 
 // Load THT_* env vars from .env (project root = ctx.cwd).
 function loadEnvFromDotenv(ctx) {
-	const fs = require("node:fs");
-	const path = require("node:path");
-	const envPath = path.join(ctx.cwd, ".env");
+	const envPath = join(ctx.cwd, ".env");
 	try {
-		const raw = fs.readFileSync(envPath, "utf8");
+		const raw = readFileSync(envPath, "utf8");
 		for (const line of raw.split("\n")) {
 			const trimmed = line.trim();
 			if (!trimmed || trimmed.startsWith("#")) continue;
@@ -262,7 +264,8 @@ function loadEnvFromDotenv(ctx) {
 			const key = trimmed.slice(0, idx).trim();
 			const value = trimmed.slice(idx + 1).trim();
 			if (key.startsWith("THT_") || key.startsWith("PSD_")) {
-				process.env[key] = value;
+				// Managed runtime configuration/principal values select the authoritative repository.
+				process.env[key] ??= value;
 			}
 		}
 	} catch {
@@ -276,6 +279,30 @@ function tht(ctx, args, input) {
 	return execFileSync("tht", args, { cwd: ctx.cwd, encoding: "utf8", input });
 }
 
+const contextLanguages = new WeakMap();
+
+function sessionLanguage(ctx, sessionId) {
+	const manifest = JSON.parse(tht(ctx, ["session", "ensure-interaction-language", sessionId, "--json"]));
+	// Fail closed: an unreadable manifest must not silently select a browser/env default.
+	if (typeof manifest.interaction_language !== "string" || !manifest.interaction_language)
+		throw new Error("Session interaction language is unavailable");
+	new Intl.Locale(manifest.interaction_language);
+	new Intl.Locale(manifest.workspace_language);
+	contextLanguages.set(ctx, manifest.interaction_language);
+	return manifest;
+}
+
+function languageContext(manifest) {
+	return "\n\n<session-language>\n" +
+		`interaction_language=${manifest.interaction_language}\n` +
+		`workspace_language=${manifest.workspace_language}\n` +
+		"Use interaction_language for all newly generated reviewer questions, explanations, and choices. " +
+		"This persisted session setting is authoritative on every turn, including resume and steering. " +
+		"Preserve workspace documents, quoted sources, prior decisions, SQL, identifiers and literal values. " +
+		"Interpret domain terms in workspace_language. Instruction/example language does not change these settings.\n" +
+		"</session-language>";
+}
+
 // Runs a privileged tht call; converts any failure into an actionable textResult
 // (never propagates a raw "Command failed" to the model).
 function relayIfThtFails(ctx, args, recovery, input) {
@@ -589,7 +616,7 @@ async function reLoop(ctx) {
 	// hasUI is true in RPC too, so this warning would leak to the frontend.
 	if (ctx.mode === "tui")
 		await ctx.ui.notify(
-			"Esc non chiude il gate: usa Torna indietro / Esci / Altro dalle opzioni.",
+			gateText(contextLanguages.get(ctx), "escapeHelp"),
 			"warning",
 		);
 }
@@ -601,6 +628,10 @@ export default function (pi) {
 	let lastSteered = false;
 	let pendingKickoff = null;
 	let activeSessionId = null;
+	const languageFor = (ctx, session) => {
+		activeSessionId = session;
+		return sessionLanguage(ctx, session).interaction_language;
+	};
 	const announcedPhases = new Map();
 	const announceCurrentPhase = async (ctx, session) => {
 		if (ctx.mode !== "rpc" || typeof session !== "string" || !session.trim()) return;
@@ -614,6 +645,8 @@ export default function (pi) {
 		}
 	};
 	const memoryGate = createMemoryGate({
+		languageFor,
+		gateText,
 		workflow: {
 			activate: () => {
 				lockActive = true;
@@ -631,7 +664,7 @@ export default function (pi) {
 				try {
 					const result = JSON.parse(tht(ctx, ["memory", ...args]));
 					if (result.indexed === false) {
-						await ctx.ui.notify("Memory saved. Index update is incomplete; an administrator can retry it in Memory management.", "warning");
+						await ctx.ui.notify(gateText(contextLanguages.get(ctx), "memoryIndexWarning"), "warning");
 					}
 					return null;
 				} catch (error) {
@@ -743,6 +776,7 @@ export default function (pi) {
 		const raw = (event.text ?? "").trimStart();
 		// entry detection: workflow-start funziona sia da TUI sia da comando RPC `prompt`.
 		if (/^\/(nuova-domanda|riprendi-sessione)\b/.test(raw)) {
+			activeSessionId = /^\/riprendi-sessione\s+(\S+)/.exec(raw)?.[1] ?? process.env.THT_SESSION ?? null;
 			// NOTE: the source runs an ollama preflight here; ThothII defers embeddings
 			// readiness to the session's first vector op. Entry detection only:
 			lockActive = true;
@@ -763,8 +797,7 @@ export default function (pi) {
 			return { action: "transform", text: trimmed.slice(1).trimStart() };
 		if (ctx.mode === "tui") {
 			await ctx.ui.notify(
-				"Durante la sessione rispondi con i widget del gate. " +
-					"Per inviare testo libero al modello inizia la riga con '!'.",
+				gateText(contextLanguages.get(ctx), "inputHelp"),
 				"warning",
 			);
 		}
@@ -774,9 +807,10 @@ export default function (pi) {
 	// 3) BEFORE_AGENT_START: one-shot kickoff injection (appends the operational
 	//    instructions to the system prompt on the turn that starts/resumes a session).
 	pi.on("before_agent_start", async (event, ctx) => {
-		await announceCurrentPhase(ctx, process.env.THT_SESSION);
-		if (!pendingKickoff) return undefined;
-		const sessionId = process.env.THT_SESSION;
+		const sessionId = activeSessionId ?? process.env.THT_SESSION;
+		await announceCurrentPhase(ctx, sessionId);
+		const language = sessionId ? languageContext(sessionLanguage(ctx, sessionId)) : "";
+		if (!pendingKickoff) return language ? { systemPrompt: event.systemPrompt + language } : undefined;
 		const isProvidedNewSession =
 			Boolean(sessionId) && pendingKickoff === NUOVA_DOMANDA_KICKOFF_PROVIDED(sessionId);
 		const isResumeSession = pendingKickoff === RIPRENDI_KICKOFF();
@@ -802,7 +836,7 @@ export default function (pi) {
 				inject +
 				(retrievalPack
 					? "\n\n<retrieval-pack>\n" + retrievalPack + "\n</retrieval-pack>"
-					: ""),
+					: "") + language,
 		};
 	});
 
@@ -814,7 +848,7 @@ export default function (pi) {
 			lockActive = false;
 			lastSteered = false;
 		}
-		activeSessionId = null;
+		if (!pendingKickoff) activeSessionId = null;
 		announcedPhases.clear();
 		_phaseMetaCache = null;
 	});
@@ -824,7 +858,10 @@ export default function (pi) {
 	// completes, including auto-approved phases that never open a human widget.
 	pi.on("tool_result", async (event, ctx) => {
 		const session = typeof event.input?.session === "string" ? event.input.session : null;
-		if (session) await announceCurrentPhase(ctx, session);
+		if (session) {
+			activeSessionId = session;
+			await announceCurrentPhase(ctx, session);
+		}
 	});
 
 	// 5) AGENT_END prose safety net: if the model emits prose instead of a reviewer_*
@@ -936,15 +973,18 @@ export default function (pi) {
 					);
 				}
 
+				const locale = languageFor(ctx, session);
 				const options = [
 					{
 						id: "generate",
-						label: "Sì, genera il datamart",
+						label: gateText(locale, "datamartYes"),
+						label_i18n: gateText("en", "datamartYes"),
 						decision: { type: "datamart_requested", subject },
 					},
 					{
 						id: "skip",
-						label: "No, salta il datamart",
+						label: gateText(locale, "datamartNo"),
+						label_i18n: gateText("en", "datamartNo"),
 						decision: { type: "datamart_declined", subject },
 						recommended: true,
 					},
@@ -952,10 +992,13 @@ export default function (pi) {
 				const widget = buildSelectRequest({
 					id: `u${Date.now()}`,
 					phase: phaseId(ctx, curNum),
-					title: "Vuoi generare un datamart?",
+					title: gateText(locale, "datamartTitle"),
+					titleI18n: gateText("en", "datamartTitle"),
 					intro: null,
 					recommended: "skip",
-					options: options.map((option) => ({ id: option.id, label: option.label })),
+					options: options.map((option) => ({
+						id: option.id, label: option.label, label_i18n: option.label_i18n,
+					})),
 				});
 				const resp = await emitAndWait(ctx, widget);
 				const outcome = resolveSelectOutcome(options, resp);
@@ -1037,6 +1080,7 @@ export default function (pi) {
 				.every((o) => o.decision.type === "join_modified");
 			const widget = joinOnly
 				? buildJoinReviewRequest({
+					locale: languageFor(ctx, session),
 					id: `u${Date.now()}`,
 					phase,
 					title,
@@ -1293,6 +1337,7 @@ export default function (pi) {
 			lockActive = true;
 			try {
 			const { session, kind, title } = params;
+			const locale = languageFor(ctx, session);
 			let artifact = params.artifact;
 			const curNum = currentPhase(ctx, session);
 			const phase = phaseId(ctx, curNum);
@@ -1428,6 +1473,7 @@ export default function (pi) {
 						enriched,
 						show.decisions,
 						meta ? meta.emits : [],
+						locale,
 					);
 				} catch {
 					// ledger non leggibile: il riepilogo resta quello del modello
@@ -1436,18 +1482,22 @@ export default function (pi) {
 			}
 
 			const widget = buildArtifactGate({
+				locale,
 				id: `u${Date.now()}`,
 				phase,
 				title,
 				artifact,
-				action: { kind: "approve_reject", prompt: "Approvi o rifiuti?" },
+				action: {
+					kind: "approve_reject", prompt: gateText(locale, "approvalPrompt"),
+					prompt_i18n: gateText("en", "approvalPrompt"),
+				},
 			});
 			let outcome;
 			for (;;) {
 				const resp = await emitAndWait(ctx, widget);
 				outcome = resolveConfirmOutcome(resp);
 				if (outcome.kind !== "unknown") break;
-				await ctx.ui.notify("Scegli «Salva e procedi» o «Rifiuta».", "warning");
+				await ctx.ui.notify(gateText(locale, "chooseApproval"), "warning");
 			}
 			if (outcome.kind === "freetext")
 				return textResult(
@@ -1729,7 +1779,7 @@ export default function (pi) {
 						: parts[0];
 			const sid = sessionId ?? activeSessionId ?? process.env.THT_SESSION;
 			if (!sid) {
-				await ctx.ui.notify("Uso: /torna <session_id> [N]", "warning");
+				await ctx.ui.notify(gateText(contextLanguages.get(ctx), "backUsage"), "warning");
 				return;
 			}
 			const cur = currentPhase(ctx, sid);
@@ -1737,7 +1787,7 @@ export default function (pi) {
 			const target = targetArg ? parseInt(targetArg, 10) : cur - 1;
 			if (target < 1 || target >= cur) {
 				await ctx.ui.notify(
-					`Target non valido (fase corrente ${cur}).`,
+					gateText(contextLanguages.get(ctx), "backInvalid").replace("{phase}", String(cur)),
 					"warning",
 				);
 				return;

harness/.pi/prompts/nuova-domanda.md

@@ -4,3 +4,6 @@ argument-hint: "<domanda>"
 ---
 Nuova domanda ThothII: "$@"
 
+Use the session manifest's interaction_language for reviewer dialogue. Workspace
+content and SQL retain their original language and values. A managed session already
+has its language pinned; standalone `tht session new` defaults to workspace language.

harness/.pi/prompts/riprendi-sessione.md

@@ -4,3 +4,6 @@ argument-hint: "<session-id>"
 ---
 Riprendi la sessione ThothII "$1".
 
+Use the persisted interaction_language. For a legacy manifest without it, run
+`tht session ensure-interaction-language "$1" --json` before interacting. Resume
+accepts no language override. Preserve workspace content, SQL and prior decisions.

harness/.pi/skills/tht-sessione/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: tht-sessione
-description: Orchestrator of the Thoth NL->SQL workflow, phases 1-8 (question clarification, memories, rewriting, schema linking, synthesis, CTE plan, final SQL, datamart). Use when working a natural-language question inside a Thoth session.
+description: Orchestrator of the Thoth NL-to-SQL workflow, phases 1-8 (question clarification, memories, rewriting, schema linking, synthesis, CTE plan, final SQL, datamart). Use when working a natural-language question inside a Thoth session.
 ---
 
 # Thoth session workflow (phases 1-8)
@@ -17,11 +17,19 @@ confirmation and is persisted directly — an option without a payload only asks
 Continue records the complete join set), `reviewer_confirm` (gate on an artifact / phase transition). Free text
 arrives via the "Altro/Other" option or by prefixing `!` in chat.
 
-**Language contract (from the workspace `language` field):** the table/column
-descriptions and the evidence you read are written in the workspace language (e.g.
-`it` for PSD). **These instructions are in English; your output to the reviewer and
-your interpretation of domain terms follow the workspace language.** When in doubt
-about a domain term, ask the reviewer.
+**Language contract:** the session manifest's `interaction_language` controls all
+new reviewer questions, explanations, option labels and rationales, including prose
+you generate inside review artifacts. It remains authoritative throughout the session,
+including resume and steering from a browser using a different UI locale. The gate
+injects this persisted language into each model turn; the language of these instructions
+and examples does not select the output language.
+
+`workspace.language` controls workspace-owned documents, catalog descriptions, Evidence
+and interpretation of domain terms. Preserve quoted source content and prior decisions
+verbatim. Keep SQL, identifiers, literal values and workspace artifacts unchanged by
+the interaction preference. Ask about ambiguous domain terms in the interaction language.
+For a legacy manifest without the field, run `tht session ensure-interaction-language
+<id> --json` before interacting: it pins workspace language once and accepts no override.
 
 ## Phase map (advance cheat-sheet)
 
@@ -153,7 +161,8 @@ When launched with `/riprendi-sessione <id>` you have NO prior conversation —
 persisted state is your only context. Bootstrap before doing anything else:
 
 1. `tht session show <id> --json` → read `phase` (the current phase N), `status`, and
-   the manifest (`question`, `database`, `schema`).
+   the manifest (`question`, `database`, `schema`, `interaction_language`). If language
+   is absent, run `tht session ensure-interaction-language <id> --json` and use its value.
 2. Load the artifacts produced so far with `tht session documents <id> --json`, which
    returns their keys and contents directly: `question.md` (revised question),
    `schema_linking.json` (F4 output), `ctes/*.sql` + `cte_tests.json` (F6),

harness/.pi/skills/tht-sessione/projection.md.tmpl

@@ -1,6 +1,6 @@
 ---
 name: tht-sessione
-description: Orchestrator of the Thoth NL->SQL workflow, phases 1-8 (question clarification, memories, rewriting, schema linking, synthesis, CTE plan, final SQL, datamart). Use when working a natural-language question inside a Thoth session.
+description: Orchestrator of the Thoth NL-to-SQL workflow, phases 1-8 (question clarification, memories, rewriting, schema linking, synthesis, CTE plan, final SQL, datamart). Use when working a natural-language question inside a Thoth session.
 ---
 
 # Thoth session workflow (phases 1-8)
@@ -17,11 +17,19 @@ confirmation and is persisted directly — an option without a payload only asks
 Continue records the complete join set), `reviewer_confirm` (gate on an artifact / phase transition). Free text
 arrives via the "Altro/Other" option or by prefixing `!` in chat.
 
-**Language contract (from the workspace `language` field):** the table/column
-descriptions and the evidence you read are written in the workspace language (e.g.
-`it` for PSD). **These instructions are in English; your output to the reviewer and
-your interpretation of domain terms follow the workspace language.** When in doubt
-about a domain term, ask the reviewer.
+**Language contract:** the session manifest's `interaction_language` controls all
+new reviewer questions, explanations, option labels and rationales, including prose
+you generate inside review artifacts. It remains authoritative throughout the session,
+including resume and steering from a browser using a different UI locale. The gate
+injects this persisted language into each model turn; the language of these instructions
+and examples does not select the output language.
+
+`workspace.language` controls workspace-owned documents, catalog descriptions, Evidence
+and interpretation of domain terms. Preserve quoted source content and prior decisions
+verbatim. Keep SQL, identifiers, literal values and workspace artifacts unchanged by
+the interaction preference. Ask about ambiguous domain terms in the interaction language.
+For a legacy manifest without the field, run `tht session ensure-interaction-language
+<id> --json` before interacting: it pins workspace language once and accepts no override.
 
 ## Phase map (advance cheat-sheet)
 
@@ -151,7 +159,8 @@ When launched with `/riprendi-sessione <id>` you have NO prior conversation —
 persisted state is your only context. Bootstrap before doing anything else:
 
 1. `tht session show <id> --json` → read `phase` (the current phase N), `status`, and
-   the manifest (`question`, `database`, `schema`).
+   the manifest (`question`, `database`, `schema`, `interaction_language`). If language
+   is absent, run `tht session ensure-interaction-language <id> --json` and use its value.
 2. Load the artifacts produced so far with `tht session documents <id> --json`, which
    returns their keys and contents directly: `question.md` (revised question),
    `schema_linking.json` (F4 output), `ctes/*.sql` + `cte_tests.json` (F6),

harness/.pi/skills/tht-sessione/rewriting.md

@@ -12,8 +12,10 @@ The rewritten question must:
 3. Replace ambiguous terms with the concepts clarified in Phase 1, citing the
    evidence that defines them when it exists (evidence id in parentheses).
 4. Make the expected output explicit: count, list, aggregate, trend.
-5. Stay in the workspace language, in a form a second reviewer would understand
-   without having seen the conversation.
+5. Write the persisted question document in the workspace language, in a form a second
+   reviewer would understand without having seen the conversation. Explanations and
+   choices addressed to the reviewer use the manifest's interaction_language; preserve
+   domain terms, identifiers and quoted values in either presentation.
 
 Format of the proposal to the reviewer: