feat(cache-warming): lifecycle CR-4 — default-off, fresh nextWarmAt, conversation close (+CR-1 table, CR-2 scope)

CR-4a: warming defaults OFF (opt-in per conversation); re-enabling restores
the persisted interval.
CR-4b: re-arm BEFORE surface notify so post-warm updates carry the FUTURE
nextWarmAt; turnSettled/turnStarted now also push (fresh schedule after seal,
null while generating).
CR-4c: POST /conversations/:id/close — per-turn AbortController wired to the
kernel runTurn signal (partial persist + normal seal, done.reason "aborted"),
new conversationClosed hook, cache-warming disables sync + persists OFF.
Disconnect/chat.unsubscribe semantics unchanged.
CR-4d: no change needed — initial surface echo already at HEAD (stale up2 boot
on the FE probe).
CR-1: loaded-extensions emits a single custom rendererId:"table" field
(TablePayload exported; Name|Version|Trust|Activation, all trust tiers).
CR-2: SurfaceCatalogEntry.scope?: "global"|"conversation" on both surfaces.

Contracts: ui-contract 0.1.0→0.2.0, transport-contract 0.8.0→0.9.0 (additive).
907 tests pass (+13); live-verified against bin/up (warms @5s with future
nextWarmAt; mid-turn close → abortedTurn:true + done.reason aborted).
Courier: frontend-cache-warming-lifecycle-handoff.md.

4 files changed, 59 insertions, 0 deletions

diff --git a/packages/transport-http/src/app.test.ts b/packages/transport-http/src/app.test.ts
index 32e9689..c26a868 100644
--- a/packages/transport-http/src/app.test.ts
+++ b/packages/transport-http/src/app.test.ts
@@ -115,6 +115,9 @@ function createFakeOrchestrator(events: AgentEvent[]): SessionOrchestrator {
 		isActive() {
 			return false;
 		},
+		closeConversation() {
+			return { abortedTurn: false };
+		},
 		async handleMessage(input) {
 			for (const event of events) {
 				input.onEvent(event);
@@ -142,6 +145,9 @@ function createCapturingOrchestrator(): SessionOrchestrator & {
 		isActive() {
 			return false;
 		},
+		closeConversation() {
+			return { abortedTurn: false };
+		},
 		async handleMessage(input) {
 			state.received = input;
 		},
@@ -159,6 +165,9 @@ function createThrowingOrchestrator(error: Error): SessionOrchestrator {
 		isActive() {
 			return false;
 		},
+		closeConversation() {
+			return { abortedTurn: false };
+		},
 		async handleMessage() {
 			throw error;
 		},
@@ -1088,6 +1097,43 @@ describe("throughput recording + GET /metrics/throughput", () => {
 	});
 });
 
+describe("POST /conversations/:id/close", () => {
+	it("closes via the orchestrator and returns CloseConversationResponse", async () => {
+		const closeCalls: string[] = [];
+		const orchestrator: SessionOrchestrator = {
+			...createFakeOrchestrator([]),
+			closeConversation(conversationId) {
+				closeCalls.push(conversationId);
+				return { abortedTurn: true };
+			},
+		};
+		const app = createApp({
+			conversationStore: createFakeConversationStore(),
+			orchestrator,
+			credentialStore: createFakeCredentialStore([]),
+			logger: noopLogger,
+		});
+
+		const res = await app.request("/conversations/conv-9/close", { method: "POST" });
+		expect(res.status).toBe(200);
+		expect(await res.json()).toEqual({ conversationId: "conv-9", abortedTurn: true });
+		expect(closeCalls).toEqual(["conv-9"]);
+	});
+
+	it("reports abortedTurn false for an idle conversation", async () => {
+		const app = createApp({
+			conversationStore: createFakeConversationStore(),
+			orchestrator: createFakeOrchestrator([]),
+			credentialStore: createFakeCredentialStore([]),
+			logger: noopLogger,
+		});
+
+		const res = await app.request("/conversations/conv-idle/close", { method: "POST" });
+		expect(res.status).toBe(200);
+		expect(await res.json()).toEqual({ conversationId: "conv-idle", abortedTurn: false });
+	});
+});
+
 describe("GET /conversations/:id/cwd", () => {
 	it("returns null when unset", async () => {
 		const app = createApp({
diff --git a/packages/transport-http/src/app.ts b/packages/transport-http/src/app.ts
index 7778bad..11d2850 100644
--- a/packages/transport-http/src/app.ts
+++ b/packages/transport-http/src/app.ts
@@ -1,5 +1,6 @@
 import type { AgentEvent, Logger } from "@dispatch/kernel";
 import type {
+	CloseConversationResponse,
 	ConversationHistoryResponse,
 	ConversationMetricsResponse,
 	CwdResponse,
@@ -319,6 +320,14 @@ export function createApp(opts: CreateServerOptions): Hono {
 		}
 	});
 
+	app.post("/conversations/:id/close", (c) => {
+		const conversationId = c.req.param("id");
+		const { abortedTurn } = opts.orchestrator.closeConversation(conversationId);
+		log.info("conversations: closed", { conversationId, abortedTurn });
+		const body: CloseConversationResponse = { conversationId, abortedTurn };
+		return c.json(body, 200);
+	});
+
 	app.get("/conversations/:id/cwd", async (c) => {
 		const conversationId = c.req.param("id");
 		try {
diff --git a/packages/transport-http/src/extension.ts b/packages/transport-http/src/extension.ts
index 6c988a5..33b9990 100644
--- a/packages/transport-http/src/extension.ts
+++ b/packages/transport-http/src/extension.ts
@@ -28,6 +28,7 @@ export const manifest: Manifest = {
 			"/chat",
 			"/chat/warm",
 			"/conversations/:id",
+			"/conversations/:id/close",
 			"/conversations/:id/cwd",
 			"/conversations/:id/lsp",
 			"/health",
diff --git a/packages/transport-http/src/server.bun.test.ts b/packages/transport-http/src/server.bun.test.ts
index 8a719c0..a465243 100644
--- a/packages/transport-http/src/server.bun.test.ts
+++ b/packages/transport-http/src/server.bun.test.ts
@@ -64,6 +64,9 @@ function fakeOrchestrator(): SessionOrchestrator {
 		isActive() {
 			return false;
 		},
+		closeConversation() {
+			return { abortedTurn: false };
+		},
 		async handleMessage() {},
 	};
 }