feat(coding-agent): configure isolated task apply behavior

packages/coding-agent/src/task/index.ts

@@ -160,6 +160,7 @@ export function formatResultOutputFallback(result: Pick<SingleResult, "output" |
 function renderDescription(
 	agents: AgentDefinition[],
 	isolationEnabled: boolean,
+	applyIsolatedChanges: boolean,
 	disabledAgents: string[],
 	batchEnabled: boolean,
 	asyncEnabled: boolean,
@@ -187,6 +188,7 @@ function renderDescription(
 		defaultAgent: spawnPolicy.defaultAgent,
 		allowedAgentsText: spawnPolicy.allowedPromptText,
 		isolationEnabled,
+		applyIsolatedChanges,
 		batchEnabled,
 		asyncEnabled,
 		hasBlockingAgents: renderedAgents.some(agent => agent.blocking),
@@ -566,6 +568,7 @@ export class TaskTool implements AgentTool<TaskToolSchemaInstance, TaskToolDetai
 		return renderDescription(
 			this.#discoveredAgents,
 			!planMode && isolationMode !== "none",
+			this.session.settings.get("task.isolation.apply"),
 			disabledAgents,
 			this.#isBatchEnabled(),
 			this.session.settings.get("async.enabled"),

packages/coding-agent/src/task/structured-subagent.ts

@@ -300,7 +300,9 @@ export async function resolveEffectiveSubagentPolicy(
 		planMode,
 		isIsolated,
 		mergeMode: request.isolation?.merge ?? request.session.settings.get("task.isolation.merge"),
-		applyChanges: request.isolation?.apply !== false,
+		applyChanges:
+			request.isolation?.apply ??
+			(request.invocationKind === "task" ? request.session.settings.get("task.isolation.apply") : true),
 		enableLsp:
 			!planMode &&
 			(request.enableLsp ?? ((request.session.enableLsp ?? true) && request.session.settings.get("task.enableLsp"))),