feat: gate decision-type validation, force-advance, and frontend fixes

Gate (tht-gate.js):
- Pre-validate decision types against workflow.yaml before showing reviewer widget
- Reject decisions emitted by later phases (min-phase check)
- Copy top-level `kind` into artifact when model forgets it (prevents loop)
- Force-advance on reviewer_decide/schema_linking when advance:true — skip
  redundant reviewer_confirm gate

Backend:
- Emit agent_end on clean Pi exit (code 0 + bridge idle) instead of marking failed

Frontend:
- Strip <think> tags from transcript and activity panel
- Fix mermaid render with offscreen container + cleanup
- Graceful mermaid error: show source code instead of red error, fall back to table

Workflow:
- F2 now emits table_promoted and table_excluded (early schema linking decisions)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

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

@@ -129,6 +129,11 @@ export function prepareReviewerArguments(input) {
 	if (args.artifact && typeof args.artifact === "object" && args.artifact.data !== undefined) {
 		args.artifact = { ...args.artifact, data: jsonObjectOrSelf(args.artifact.data) };
 	}
+	// Models frequently forget artifact.kind while providing it at top level —
+	// copy it over so validation doesn't loop.
+	if (args.artifact && typeof args.artifact === "object" && !args.artifact.kind && args.kind) {
+		args.artifact = { ...args.artifact, kind: args.kind };
+	}
 	return args;
 }
 
@@ -275,6 +280,52 @@ function phaseId(ctx, num) {
 	const p = meta.phases.find((x) => x.num === num);
 	return p ? p.id : "?";
 }
+// Known decision types from workflow.yaml emits + meta types. Pre-validates decision
+// payloads BEFORE showing the reviewer widget so a typo in the type name doesn't waste
+// a human interaction (the CLI would reject it only after the reviewer has already picked).
+let _knownTypes = null;
+function knownDecisionTypes(ctx) {
+	if (_knownTypes) return _knownTypes;
+	const meta = phaseMeta(ctx);
+	const types = new Set([
+		"phase_approved", "phase_auto_approved", "phase_reopened",
+		"phase_skipped", "decision_retracted",
+	]);
+	for (const p of meta.phases) {
+		for (const t of (p.emits || [])) types.add(t);
+	}
+	_knownTypes = types;
+	return types;
+}
+function decisionMinPhaseMap(ctx) {
+	const meta = phaseMeta(ctx);
+	const mins = {};
+	for (const p of meta.phases) {
+		for (const t of (p.emits || [])) {
+			if (!(t in mins) || p.num < mins[t]) mins[t] = p.num;
+		}
+	}
+	return mins;
+}
+function validateDecisionTypes(ctx, options, session) {
+	const known = knownDecisionTypes(ctx);
+	for (const o of options) {
+		if (o.decision && !known.has(o.decision.type)) {
+			return `Tipo di decisione '${o.decision.type}' non valido. Tipi ammessi: ${[...known].join(", ")}. Correggi e riprova.`;
+		}
+	}
+	if (session) {
+		const cur = currentPhase(ctx, session);
+		const mins = decisionMinPhaseMap(ctx);
+		for (const o of options) {
+			if (o.decision && mins[o.decision.type] && mins[o.decision.type] > cur) {
+				return `Tipo '${o.decision.type}' ammesso dalla Fase ${mins[o.decision.type]}, sessione alla Fase ${cur}. Chiudi prima la fase corrente.`;
+			}
+		}
+	}
+	return null;
+}
+
 // Full phase descriptor {id, num, name} for the v2 phase-summary payload's `phase`.
 function phaseMetaForNum(ctx, num) {
 	const meta = phaseMeta(ctx);
@@ -316,6 +367,21 @@ function advanceIfReady(ctx, session) {
 	}
 }
 
+// Unconditional phase advance — the reviewer already approved via the widget interaction
+// (reviewer_decide selection IS the human confirmation). Used when reviewer_decide persists
+// substantive decisions with advance:true, so no separate reviewer_confirm gate is needed.
+function forceAdvance(ctx, session) {
+	try {
+		tht(ctx, ["phase", "advance", "--session", session]);
+		return { advanced: true };
+	} catch (e) {
+		return {
+			advanced: false,
+			error: (e.stderr || e.message || String(e)).toString().trim(),
+		};
+	}
+}
+
 // --- widget emission + wait — usa l'API UI NATIVA di Pi (ctx.ui.input) --------
 //
 // emitAndWait(ctx, descriptor) sends the widget-descriptor as JSON in the `title`
@@ -662,6 +728,8 @@ export default function (pi) {
 		async execute(_id, params, _signal, _onUpdate, ctx) {
 			lockActive = true;
 			const { session, title, options: opts, intro, advance } = params;
+			const typeErr = validateDecisionTypes(ctx, opts, session);
+			if (typeErr) return textResult(typeErr);
 			const phase = phaseId(ctx, currentPhase(ctx, session));
 			const recommended = opts.find((o) => o.recommended)?.id ?? null;
 
@@ -734,6 +802,8 @@ export default function (pi) {
 		async execute(_id, params, _signal, _onUpdate, ctx) {
 			lockActive = true;
 			const { session, title, options: opts, advance } = params;
+			const typeErr = validateDecisionTypes(ctx, opts, session);
+			if (typeErr) return textResult(typeErr);
 			const phase = phaseId(ctx, currentPhase(ctx, session));
 			const toAdd = [];
 			const meritOptions = opts
@@ -813,12 +883,17 @@ export default function (pi) {
 					toAdd.push(d);
 				}
 			}
-			if (advance) advanceIfReady(ctx, session);
-			return textResult(
-				toAdd.length
-					? `Registrate ${toAdd.length} decisioni: ${toAdd.map((d) => d.type).join(", ")}.`
-					: "Nessuna decisione registrata (il reviewer non ha selezionato opzioni di merito).",
-			);
+			if (!toAdd.length) {
+				const adv = advance ? advanceIfReady(ctx, session) : { advanced: false };
+				const msg = "Nessuna decisione registrata (il reviewer non ha selezionato opzioni di merito).";
+				return textResult(adv.advanced ? msg + " Fase avanzata automaticamente." : msg);
+			}
+			// Decisions were recorded AND advance requested: the reviewer's selection IS the
+			// approval — force-advance without a separate reviewer_confirm gate.
+			const adv = advance ? forceAdvance(ctx, session) : { advanced: false };
+			const parts = [`Registrate ${toAdd.length} decisioni: ${toAdd.map((d) => d.type).join(", ")}.`];
+			if (adv.advanced) parts.push("Fase avanzata automaticamente — nessun gate aggiuntivo necessario.");
+			return textResult(parts.join(" "));
 		},
 	});
 
@@ -924,8 +999,10 @@ export default function (pi) {
 			const eSync = relayIfThtFails(ctx, ["session", "sync-schema-linking", session], "");
 			if (eSync) return eSync;
 
-			if (advance) advanceIfReady(ctx, session);
-			return textResult(`Schema linking registrato dal reviewer (${n} tabelle + colonne curate).`);
+			const adv = advance ? forceAdvance(ctx, session) : { advanced: false };
+			const parts = [`Schema linking registrato dal reviewer (${n} tabelle + colonne curate). schema_linking.json scritto.`];
+			if (adv.advanced) parts.push("Fase avanzata automaticamente — nessun gate aggiuntivo necessario.");
+			return textResult(parts.join(" "));
 		},
 	});
 

harness/tests/test_decision_min_phase.py

@@ -16,7 +16,7 @@ from tht.workflow import load_workflow
         ("concept_clarified", 1),
         ("memory_rejected", 2),
         ("question_rewritten", 3),
-        ("table_promoted", 4),
+        ("table_promoted", 2),
         ("column_corrected", 4),
         ("evidence_accepted", 4),
         ("value_grounded", 4),

harness/workflow.yaml

@@ -21,7 +21,7 @@ phases:
     advance: auto_if_empty
     prerequisites: []
     artifacts_out: []
-    emits: [memory_rejected]
+    emits: [memory_rejected, table_promoted, table_excluded]
   - id: F3
     name: riscrittura
     advance: kind:phase