Method mark_complete

src/context/task_storage.rs:414–436

Transition a task to Complete status, setting `completed_at` to now and `branch_name`. Guarded: only updates tasks with status = RUNNING. If the task exists but is no longer RUNNING (e.g., already CANCELLED), returns the current task as-is (no-op).

(
        &self,
        id: &str,
        branch_name: &str,
    )

    /// Guarded: only updates tasks with status = RUNNING. If the task exists but is
    /// no longer RUNNING (e.g., already CANCELLED), returns the current task as-is (no-op).
    pub async fn mark_complete(
        &self,
        id: &str,
        branch_name: &str,
    ) -> Result<Task, Box<dyn std::error::Error + Send + Sync>> {
        let conn = Arc::clone(&self.conn);
        let id = id.to_string();
        let branch_name = branch_name.to_string();
        tokio::task::spawn_blocking(move || {
            let conn = conn.lock().map_err(|e| format!("Lock error: {e}"))?;
            let now = chrono::Utc::now().to_rfc3339();
            let rows_affected = conn.execute(
                "UPDATE tasks SET status = 'COMPLETE', completed_at = ?1, branch_name = ?2 WHERE id = ?3 AND status = 'RUNNING'",
                rusqlite::params![now, branch_name, id],
            )?;
            if rows_affected == 0 {
                // Task may not exist, or may already be in a terminal state (e.g. CANCELLED)
                return read_task_by_id(&conn, &id);
            }
            read_task_by_id(&conn, &id)
        })
        .await?
    }

    /// Transition a task to Failed status, setting `completed_at` to now and `error_message`.
    ///