# TASK 1.1: Create MonitorSpec Entity and EF Configuration

## Summary

Create the `MonitorSpec` entity that represents a versioned, executable monitor definition stored in the database. This is the core configuration object that defines what the anomaly detector should monitor.

## Dependencies

- None (first task)

## Files to Create

### 1. `backend/Kds.Ai.Data/Entities/MonitorSpec.cs`

```csharp
using Kds.Ai.Data.Enums;

namespace Kds.Ai.Data.Entities;

public sealed class MonitorSpec
{
    public Guid Id { get; set; }
    
    /// <summary>
    /// Human-readable name for the monitor (e.g., "Prep Time Anomaly Monitor")
    /// </summary>
    public required string Name { get; set; }
    
    /// <summary>
    /// LLM system prompt that defines the agent's behavior
    /// </summary>
    public required string SystemPrompt { get; set; }
    
    /// <summary>
    /// JSON configuration for thresholds, lookback periods, etc.
    /// </summary>
    public string? Configuration { get; set; }
    
    /// <summary>
    /// Current state of the monitor (Draft, Active, Paused, Archived)
    /// </summary>
    public MonitorState State { get; set; }
    
    /// <summary>
    /// When this monitor spec was created
    /// </summary>
    public DateTimeOffset CreatedAt { get; set; }
    
    /// <summary>
    /// When this monitor was last updated
    /// </summary>
    public DateTimeOffset? UpdatedAt { get; set; }
    
    /// <summary>
    /// Timestamp of the last successful run
    /// </summary>
    public DateTimeOffset? LastRunAt { get; set; }
    
    /// <summary>
    /// Navigation property to execution history
    /// </summary>
    public ICollection<MonitorRun> Runs { get; set; } = [];
}
```

### 2. `backend/Kds.Ai.Data/Enums/MonitorState.cs`

```csharp
namespace Kds.Ai.Data.Enums;

/// <summary>
/// Represents the lifecycle state of a monitor specification
/// </summary>
public enum MonitorState
{
    /// <summary>
    /// Monitor is being configured and is not yet ready to run
    /// </summary>
    Draft,
    
    /// <summary>
    /// Monitor is active and will be executed on schedule
    /// </summary>
    Active,
    
    /// <summary>
    /// Monitor is temporarily paused and will not run
    /// </summary>
    Paused,
    
    /// <summary>
    /// Monitor is archived and no longer in use
    /// </summary>
    Archived
}
```

### 3. `backend/Kds.Ai.Data/Configurations/MonitorSpecConfiguration.cs`

```csharp
using Kds.Ai.Data.Entities;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;

namespace Kds.Ai.Data.Configurations;

public sealed class MonitorSpecConfiguration : IEntityTypeConfiguration<MonitorSpec>
{
    public void Configure(EntityTypeBuilder<MonitorSpec> builder)
    {
        builder.ToTable("MonitorSpecs");
        
        builder.HasKey(x => x.Id);
        
        builder.Property(x => x.Name)
            .IsRequired()
            .HasMaxLength(200);
        
        builder.Property(x => x.SystemPrompt)
            .IsRequired()
            .HasColumnType("longtext");
        
        builder.Property(x => x.Configuration)
            .HasColumnType("longtext");
        
        builder.Property(x => x.State)
            .IsRequired()
            .HasMaxLength(50);
        
        builder.Property(x => x.CreatedAt)
            .IsRequired();
        
        // Indexes for common queries
        builder.HasIndex(x => x.Name);
        builder.HasIndex(x => x.State);
    }
}
```

## Files to Modify

### 4. `backend/Kds.Ai.Data/KdsAiDbContext.cs`

Add DbSet property:

```csharp
public DbSet<MonitorSpec> MonitorSpecs => Set<MonitorSpec>();
```

Note: Configuration is automatically applied via `ApplyConfigurationsFromAssembly` - no manual registration needed.

## Acceptance Criteria

- [ ] `MonitorSpec` entity created with all specified properties
- [ ] `MonitorState` enum created with Draft, Active, Paused, Archived values
- [ ] Fluent API configuration follows project conventions (no data annotations on entity)
- [ ] Enum properties converted to strings (per project convention via `ConfigureConventions`)
- [ ] Proper indexes defined for `Name` and `State`
- [ ] DbSet registered in `KdsAiDbContext`
- [ ] Solution builds without errors

## Notes

- Follow existing patterns from `AlertEvent` entity and `AlertEventConfiguration`
- The `Configuration` field stores JSON; parsing will be handled at the service layer
- `MonitorRun` navigation property will be populated in TASK 1.2
- Use `sealed` class modifier per project convention
- Configurations are auto-discovered via `ApplyConfigurationsFromAssembly`