fix: cron sessions inherit allowAgents from parent agent config (#1771)

When a cron job runs in isolated mode, the sessions_spawn tool now correctly
inherits the allowAgents permissions from the parent agent's config.

The fix adds a requesterAgentIdOverride parameter that flows through the
tool creation chain:
- resolveEffectiveToolPolicy() extracts the correct agentId from the session key
- This agentId is passed to sessions_spawn and agents_list tools
- The tools use this override instead of re-parsing the session key

This fixes #1767

src/agents/tools/agents-list-tool.ts

@@ -19,7 +19,11 @@ type AgentListEntry = {
   configured: boolean;
 };
 
-export function createAgentsListTool(opts?: { agentSessionKey?: string }): AnyAgentTool {
+export function createAgentsListTool(opts?: {
+  agentSessionKey?: string;
+  /** Explicit agent ID override for cron/hook sessions. */
+  requesterAgentIdOverride?: string;
+}): AnyAgentTool {
   return {
     label: "Agents",
     name: "agents_list",
@@ -37,7 +41,7 @@ export function createAgentsListTool(opts?: { agentSessionKey?: string }): AnyAg
             })
           : alias;
       const requesterAgentId = normalizeAgentId(
-        parseAgentSessionKey(requesterInternalKey)?.agentId ?? DEFAULT_AGENT_ID,
+        opts?.requesterAgentIdOverride ?? parseAgentSessionKey(requesterInternalKey)?.agentId ?? DEFAULT_AGENT_ID,
       );
 
       const allowAgents = resolveAgentConfig(cfg, requesterAgentId)?.subagents?.allowAgents ?? [];