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/tools/cron_list.rs

@@ -0,0 +1,101 @@
+use super::traits::{Tool, ToolResult};
+use crate::config::Config;
+use crate::cron;
+use async_trait::async_trait;
+use serde_json::json;
+use std::sync::Arc;
+
+pub struct CronListTool {
+    config: Arc<Config>,
+}
+
+impl CronListTool {
+    pub fn new(config: Arc<Config>) -> Self {
+        Self { config }
+    }
+}
+
+#[async_trait]
+impl Tool for CronListTool {
+    fn name(&self) -> &str {
+        "cron_list"
+    }
+
+    fn description(&self) -> &str {
+        "List all scheduled cron jobs"
+    }
+
+    fn parameters_schema(&self) -> serde_json::Value {
+        json!({
+            "type": "object",
+            "properties": {},
+            "additionalProperties": false
+        })
+    }
+
+    async fn execute(&self, _args: serde_json::Value) -> anyhow::Result<ToolResult> {
+        if !self.config.cron.enabled {
+            return Ok(ToolResult {
+                success: false,
+                output: String::new(),
+                error: Some("cron is disabled by config (cron.enabled=false)".to_string()),
+            });
+        }
+
+        match cron::list_jobs(&self.config) {
+            Ok(jobs) => Ok(ToolResult {
+                success: true,
+                output: serde_json::to_string_pretty(&jobs)?,
+                error: None,
+            }),
+            Err(e) => Ok(ToolResult {
+                success: false,
+                output: String::new(),
+                error: Some(e.to_string()),
+            }),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::config::Config;
+    use tempfile::TempDir;
+
+    fn test_config(tmp: &TempDir) -> Arc<Config> {
+        let config = Config {
+            workspace_dir: tmp.path().join("workspace"),
+            config_path: tmp.path().join("config.toml"),
+            ..Config::default()
+        };
+        std::fs::create_dir_all(&config.workspace_dir).unwrap();
+        Arc::new(config)
+    }
+
+    #[tokio::test]
+    async fn returns_empty_list_when_no_jobs() {
+        let tmp = TempDir::new().unwrap();
+        let cfg = test_config(&tmp);
+        let tool = CronListTool::new(cfg);
+
+        let result = tool.execute(json!({})).await.unwrap();
+        assert!(result.success);
+        assert_eq!(result.output.trim(), "[]");
+    }
+
+    #[tokio::test]
+    async fn errors_when_cron_disabled() {
+        let tmp = TempDir::new().unwrap();
+        let mut cfg = (*test_config(&tmp)).clone();
+        cfg.cron.enabled = false;
+        let tool = CronListTool::new(Arc::new(cfg));
+
+        let result = tool.execute(json!({})).await.unwrap();
+        assert!(!result.success);
+        assert!(result
+            .error
+            .unwrap_or_default()
+            .contains("cron is disabled"));
+    }
+}