fix(plugins): late-binding subagent runtime for non-gateway load paths (#46648)

Merged via squash.

Prepared head SHA: 44742652c9
Co-authored-by: jalehman <550978+jalehman@users.noreply.github.com>
Co-authored-by: jalehman <550978+jalehman@users.noreply.github.com>
Reviewed-by: @jalehman

src/auto-reply/reply/agent-runner-memory.ts

@@ -494,6 +494,7 @@ export async function runMemoryFlushIfNeeded(params: {
           ...embeddedContext,
           ...senderContext,
           ...runBaseParams,
+          allowGatewaySubagentBinding: true,
           trigger: "memory",
           memoryFlushWritePath,
           prompt: resolveMemoryFlushPromptForRun({