fix(coordinator): reconcile durable runtime events

packages/coding-agent/src/coordinator-mcp/question-state.ts

@@ -349,7 +349,8 @@ async function readJson<T>(file: string): Promise<T | null> {
 		return JSON.parse(await fs.readFile(file, "utf8")) as T;
 	} catch (error) {
 		if ((error as NodeJS.ErrnoException).code === "ENOENT") return null;
-		throw new Error("state_corrupt");
+		if (error instanceof SyntaxError) throw new Error("state_corrupt");
+		throw error;
 	}
 }
 function assertTransaction(transaction: CoordinatorSessionTransactionV1, namespaceId: string, sessionId: string): void {

packages/coding-agent/src/coordinator-mcp/server.ts

@@ -6055,6 +6055,7 @@ export function createCoordinatorMcpServer(options: CoordinatorMcpServerOptions
 						const reportPath = path.join(namespaceDir, "reports", `${reportId}.json`);
 						await writeJsonFile(reportPath, report);
 						await appendCoordinatorEvent(namespaceDir, {
+							...(sessionId == null ? { stableId: `report-written:${reportId}` } : {}),
 							kind: "report.written",
 							sessionId,
 							turnId: typeof args.turn_id === "string" ? args.turn_id : null,

packages/coding-agent/test/coordinator-mcp-server.test.ts

@@ -1756,6 +1756,10 @@ console.log(JSON.stringify(await appendCoordinatorEventForTest(${JSON.stringify(
 		await expect(server.callTool("gjc_coordinator_read_coordination_status")).resolves.toMatchObject({
 			summary: { reports: 1 },
 		});
+		const events = await server.callTool("gjc_coordinator_watch_events", { after_seq: 0 });
+		expect(
+			(events.events as Array<Record<string, unknown>>).filter(event => event.kind === "report.written"),
+		).toHaveLength(1);
 	});
 	it("fails closed when a same-generation successor has a different endpoint incarnation", async () => {
 		const root = await tempRoot();