fix(agents): wire useTaskSystem config flag into Sisyphus and Hephaestus

The experimental.task_system flag was defined in config but never
passed through to agent creation, so the task system prompt switch
was always off.

src/agents/builtin-agents.ts

@@ -63,7 +63,8 @@ export async function createBuiltinAgents(
   customAgentSummaries?: unknown,
   browserProvider?: BrowserAutomationProvider,
   uiSelectedModel?: string,
-  disabledSkills?: Set<string>
+  disabledSkills?: Set<string>,
+  useTaskSystem = false
 ): Promise<Record<string, AgentConfig>> {
   const connectedProviders = readConnectedProvidersCache()
   // IMPORTANT: Do NOT call OpenCode client APIs during plugin initialization.
@@ -134,6 +135,7 @@ export async function createBuiltinAgents(
     mergedCategories,
     directory,
     userCategories: categories,
+    useTaskSystem,
   })
   if (sisyphusConfig) {
     result["sisyphus"] = sisyphusConfig
@@ -150,6 +152,7 @@ export async function createBuiltinAgents(
     availableCategories,
     mergedCategories,
     directory,
+    useTaskSystem,
   })
   if (hephaestusConfig) {
     result["hephaestus"] = hephaestusConfig

src/agents/builtin-agents/atlas-agent.ts

@@ -17,6 +17,7 @@ export function maybeCreateAtlasConfig(input: {
   availableSkills: AvailableSkill[]
   mergedCategories: Record<string, CategoryConfig>
   userCategories?: CategoriesConfig
+  useTaskSystem?: boolean
 }): AgentConfig | undefined {
   const {
     disabledAgents,

src/agents/builtin-agents/general-agents.ts

@@ -22,6 +22,7 @@ export function collectPendingBuiltinAgents(input: {
   uiSelectedModel?: string
   availableModels: Set<string>
   disabledSkills?: Set<string>
+  useTaskSystem?: boolean
 }): { pendingAgentConfigs: Map<string, AgentConfig>; availableAgents: AvailableAgent[] } {
   const {
     agentSources,

src/agents/builtin-agents/hephaestus-agent.ts

@@ -19,6 +19,7 @@ export function maybeCreateHephaestusConfig(input: {
   availableCategories: AvailableCategory[]
   mergedCategories: Record<string, CategoryConfig>
   directory?: string
+  useTaskSystem: boolean
 }): AgentConfig | undefined {
   const {
     disabledAgents,
@@ -31,6 +32,7 @@ export function maybeCreateHephaestusConfig(input: {
     availableCategories,
     mergedCategories,
     directory,
+    useTaskSystem,
   } = input
 
   if (disabledAgents.includes("hephaestus")) return undefined
@@ -66,7 +68,8 @@ export function maybeCreateHephaestusConfig(input: {
     availableAgents,
     undefined,
     availableSkills,
-    availableCategories
+    availableCategories,
+    useTaskSystem
   )
 
   hephaestusConfig = { ...hephaestusConfig, variant: hephaestusResolvedVariant ?? "medium" }

src/agents/builtin-agents/sisyphus-agent.ts

@@ -21,6 +21,7 @@ export function maybeCreateSisyphusConfig(input: {
   mergedCategories: Record<string, CategoryConfig>
   directory?: string
   userCategories?: CategoriesConfig
+  useTaskSystem: boolean
 }): AgentConfig | undefined {
   const {
     disabledAgents,
@@ -34,6 +35,7 @@ export function maybeCreateSisyphusConfig(input: {
     availableCategories,
     mergedCategories,
     directory,
+    useTaskSystem,
   } = input
 
   const sisyphusOverride = agentOverrides["sisyphus"]
@@ -67,7 +69,8 @@ export function maybeCreateSisyphusConfig(input: {
     availableAgents,
     undefined,
     availableSkills,
-    availableCategories
+    availableCategories,
+    useTaskSystem
   )
 
   if (sisyphusResolvedVariant) {

src/plugin-handlers/agent-config-handler.ts

@@ -58,6 +58,7 @@ export async function applyAgentConfig(params: {
     params.pluginConfig.browser_automation_engine?.provider ?? "playwright";
   const currentModel = params.config.model as string | undefined;
   const disabledSkills = new Set<string>(params.pluginConfig.disabled_skills ?? []);
+  const useTaskSystem = params.pluginConfig.experimental?.task_system ?? false;
 
   const builtinAgents = await createBuiltinAgents(
     migratedDisabledAgents,
@@ -71,6 +72,7 @@ export async function applyAgentConfig(params: {
     browserProvider,
     currentModel,
     disabledSkills,
+    useTaskSystem,
   );
 
   const includeClaudeAgents = params.pluginConfig.claude_code?.agents ?? true;
@@ -101,7 +103,6 @@ export async function applyAgentConfig(params: {
       sisyphus: builtinAgents.sisyphus,
     };
 
-    const useTaskSystem = params.pluginConfig.experimental?.task_system ?? false;
     agentConfig["sisyphus-junior"] = createSisyphusJuniorAgentWithOverrides(
       params.pluginConfig.agents?.["sisyphus-junior"],
       undefined,