feat(dashboard): task system with DB persistence, CRUD endpoints, frontend API integration

backend/Controllers/DashboardController.cs

@@ -1,12 +1,18 @@
 using Microsoft.AspNetCore.Mvc;
+using Nexus.Api.Data;
 using Nexus.Api.Models;
+using Nexus.Api.Repositories;
 using Nexus.Api.Services;
 
 namespace Nexus.Api.Controllers;
 
 [ApiController]
 [Route("api/dashboard")]
-public class DashboardController(OpenClawGatewayClient gateway, ILogger<DashboardController> logger)
+public class DashboardController(
+    OpenClawGatewayClient gateway,
+    ITaskRepository taskRepo,
+    IActivityRepository activityRepo,
+    ILogger<DashboardController> logger)
     : ControllerBase
 {
     /// <summary>
@@ -211,8 +217,156 @@ public class DashboardController(OpenClawGatewayClient gateway, ILogger<Dashboar
         return Ok(models);
     }
 
+    // ========== Task Endpoints ==========
+
+    /// <summary>
+    /// Returns all non-done tasks (status != 'Done'), ordered by creation date descending.
+    /// </summary>
+    [HttpGet("tasks")]
+    public async Task<List<DashboardTaskDto>> GetTasks(CancellationToken ct)
+    {
+        try
+        {
+            var tasks = await taskRepo.GetAllAsync(ct);
+            return tasks
+                .Where(t => !string.Equals(t.State, "Done", StringComparison.OrdinalIgnoreCase))
+                .OrderByDescending(t => t.CreatedAt)
+                .Select(MapToDto)
+                .ToList();
+        }
+        catch (Exception ex)
+        {
+            logger.LogWarning(ex, "Dashboard tasks fetch failed");
+            return new List<DashboardTaskDto>();
+        }
+    }
+
+    /// <summary>
+    /// Creates a new task and logs an activity event.
+    /// </summary>
+    [HttpPost("tasks")]
+    public async Task<ActionResult<DashboardTaskDto>> CreateTask(
+        [FromBody] CreateDashboardTaskRequest request, CancellationToken ct)
+    {
+        if (string.IsNullOrWhiteSpace(request.Title))
+            return BadRequest(new { error = "Title is required." });
+
+        var task = new WorkTask
+        {
+            Title = request.Title.Trim(),
+            Detail = request.Detail?.Trim(),
+            Source = string.IsNullOrWhiteSpace(request.Source) ? "bao" : request.Source.Trim(),
+            Priority = string.IsNullOrWhiteSpace(request.Priority) ? "Normal" : request.Priority.Trim(),
+            AssignedTo = request.AssignedTo?.Trim(),
+        };
+
+        await taskRepo.AddAsync(task, ct);
+        await activityRepo.AddAsync(new ActivityEvent
+        {
+            Type = "task",
+            Message = $"Task \"{task.Title}\" created ({task.Source})"
+        }, ct);
+
+        return Created($"/api/dashboard/tasks/{task.Id}", MapToDto(task));
+    }
+
+    /// <summary>
+    /// Updates an existing task (title, detail, source, priority, assignedTo).
+    /// </summary>
+    [HttpPut("tasks/{id:guid}")]
+    public async Task<ActionResult<DashboardTaskDto>> UpdateTask(
+        Guid id, [FromBody] UpdateDashboardTaskRequest request, CancellationToken ct)
+    {
+        var task = await taskRepo.GetByIdAsync(id, ct);
+        if (task is null)
+            return NotFound(new { error = "Task not found." });
+
+        if (!string.IsNullOrWhiteSpace(request.Title))
+            task.Title = request.Title.Trim();
+        if (request.Detail is not null)
+            task.Detail = string.IsNullOrWhiteSpace(request.Detail) ? null : request.Detail.Trim();
+        if (!string.IsNullOrWhiteSpace(request.Source))
+            task.Source = request.Source.Trim();
+        if (!string.IsNullOrWhiteSpace(request.Priority))
+            task.Priority = request.Priority.Trim();
+        if (request.AssignedTo is not null)
+            task.AssignedTo = string.IsNullOrWhiteSpace(request.AssignedTo) ? null : request.AssignedTo.Trim();
+
+        await taskRepo.UpdateAsync(task, ct);
+        await activityRepo.AddAsync(new ActivityEvent
+        {
+            Type = "task",
+            Message = $"Task \"{task.Title}\" updated"
+        }, ct);
+
+        return Ok(MapToDto(task));
+    }
+
+    /// <summary>
+    /// Deletes a task (only if status is 'Done' or 'Backlog').
+    /// </summary>
+    [HttpDelete("tasks/{id:guid}")]
+    public async Task<ActionResult> DeleteTask(Guid id, CancellationToken ct)
+    {
+        var task = await taskRepo.GetByIdAsync(id, ct);
+        if (task is null)
+            return NotFound(new { error = "Task not found." });
+
+        if (!TaskStateHelper.IsDoneOrBacklog(task.State))
+            return StatusCode(403, new { error = "Only tasks in 'Done' or 'Backlog' state can be deleted." });
+
+        await activityRepo.AddAsync(new ActivityEvent
+        {
+            Type = "task",
+            Message = $"Task \"{task.Title}\" deleted"
+        }, ct);
+        await taskRepo.DeleteAsync(task, ct);
+
+        return NoContent();
+    }
+
+    /// <summary>
+    /// Changes the status of a task.
+    /// </summary>
+    [HttpPatch("tasks/{id:guid}/status")]
+    public async Task<ActionResult<DashboardTaskDto>> UpdateTaskStatus(
+        Guid id, [FromBody] UpdateDashboardTaskStatusRequest request, CancellationToken ct)
+    {
+        if (!TaskStateHelper.IsValidState(request.Status))
+            return BadRequest(new { error = $"Unsupported status: '{request.Status}'. Valid: {string.Join(", ", TaskStateHelper.AllStates)}" });
+
+        var task = await taskRepo.GetByIdAsync(id, ct);
+        if (task is null)
+            return NotFound(new { error = "Task not found." });
+
+        var canonicalState = TaskStateHelper.AllStates.First(s =>
+            s.Equals(request.Status, StringComparison.OrdinalIgnoreCase));
+        task.State = canonicalState;
+
+        await taskRepo.UpdateAsync(task, ct);
+        await activityRepo.AddAsync(new ActivityEvent
+        {
+            Type = "task",
+            Message = $"Task \"{task.Title}\" → {canonicalState}"
+        }, ct);
+
+        return Ok(MapToDto(task));
+    }
+
     // ========== Helpers ==========
 
+    private static DashboardTaskDto MapToDto(WorkTask t) => new(
+        t.Id,
+        t.Title,
+        t.Detail,
+        t.Source,
+        t.State,
+        t.Priority,
+        t.AssignedTo,
+        t.CreatedAt,
+        t.UpdatedAt
+    );
+
     private static DateTimeOffset ParseTimestamp(string timestamp)
     {
         if (DateTimeOffset.TryParse(timestamp, null, System.Globalization.DateTimeStyles.None, out var dt))