Implement cron job management tools and types

- Added `JobType`, `SessionTarget`, `Schedule`, `DeliveryConfig`, `CronJob`, `CronRun`, and `CronJobPatch` types in `src/cron/types.rs` for cron job configuration and management.
- Introduced `CronAddTool`, `CronListTool`, `CronRemoveTool`, `CronRunTool`, `CronRunsTool`, and `CronUpdateTool` in `src/tools` for adding, listing, removing, running, and updating cron jobs.
- Updated the `run` function in `src/daemon/mod.rs` to conditionally start the scheduler based on the cron configuration.
- Modified command-line argument parsing in `src/lib.rs` and `src/main.rs` to support new cron job commands.
- Enhanced the onboarding wizard in `src/onboard/wizard.rs` to include cron configuration.
- Added tests for cron job tools to ensure functionality and error handling.

src/daemon/mod.rs

@@ -71,7 +71,7 @@ pub async fn run(config: Config, host: String, port: u16) -> Result<()> {
         ));
     }
 
-    {
+    if config.cron.enabled {
         let scheduler_cfg = config.clone();
         handles.push(spawn_component_supervisor(
             "scheduler",
@@ -82,6 +82,9 @@ pub async fn run(config: Config, host: String, port: u16) -> Result<()> {
                 async move { crate::cron::scheduler::run(cfg).await }
             },
         ));
+    } else {
+        crate::health::mark_component_ok("scheduler");
+        tracing::info!("Cron disabled; scheduler supervisor not started");
     }
 
     println!("🧠 ZeroClaw daemon started");