feat(ideas): add idea creator, grant calls and applications

Implement the idea creator and application generator: idea status workflow, social canvas card, grant call windows with 409 when closed, and an LLM-backed idea assistant with offline fallback.

backend/Application/Abstractions/IdeaContracts.cs

@@ -0,0 +1,59 @@
+using TarninaHub.Application.Dtos;
+
+namespace TarninaHub.Application.Abstractions;
+
+public interface IIdeaService
+{
+    Task<IdeaResponse> CreateAsync(string authorId, CreateIdeaRequest request, CancellationToken cancellationToken);
+
+    Task<IdeaResponse?> GetAsync(string ideaId, CancellationToken cancellationToken);
+
+    Task<IReadOnlyList<IdeaResponse>> ListForAuthorAsync(string authorId, CancellationToken cancellationToken);
+
+    Task<IdeaResponse?> UpdateAsync(string ideaId, UpdateIdeaRequest request, CancellationToken cancellationToken);
+
+    Task<IdeaCardResponse?> GetCardAsync(string ideaId, CancellationToken cancellationToken);
+
+    Task<IdeaCardResponse?> UpdateCardAsync(string ideaId, IdeaCardRequest request, CancellationToken cancellationToken);
+}
+
+public interface IIdeaAssistant
+{
+    Task<IdeaAssistResponse?> AssistAsync(
+        string ideaId,
+        IdeaAssistRequest request,
+        CancellationToken cancellationToken);
+}
+
+public interface IGrantCallService
+{
+    Task<IReadOnlyList<GrantCallResponse>> ListAsync(string? status, CancellationToken cancellationToken);
+
+    Task<GrantCallResponse?> GetAsync(string grantCallId, CancellationToken cancellationToken);
+}
+
+public enum CreateApplicationOutcome
+{
+    Created,
+    CallNotFound,
+    CallNotOpen,
+    IdeaNotFound,
+}
+
+public sealed record CreateApplicationResult(
+    CreateApplicationOutcome Outcome,
+    ApplicationResponse? Application);
+
+public interface IApplicationService
+{
+    Task<CreateApplicationResult> CreateAsync(
+        string userId,
+        CreateApplicationRequest request,
+        CancellationToken cancellationToken);
+
+    Task<ApplicationResponse?> GetAsync(string applicationId, CancellationToken cancellationToken);
+
+    Task<IReadOnlyList<ApplicationResponse>> ListForAuthorAsync(
+        string authorId,
+        CancellationToken cancellationToken);
+}

backend/Application/Dtos/ApplicationDtos.cs

@@ -0,0 +1,28 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace TarninaHub.Application.Dtos;
+
+public sealed record GrantCallResponse(
+    string Id,
+    string Name,
+    DateTimeOffset OpensAt,
+    DateTimeOffset ClosesAt,
+    string Status,
+    string? ExternalId);
+
+public sealed record CreateApplicationRequest(
+    [Required] string GrantCallId,
+    [Required] string IdeaId,
+    IReadOnlyDictionary<string, object?>? Content);
+
+public sealed record UpdateApplicationRequest(
+    IReadOnlyDictionary<string, object?>? Content,
+    string? Status);
+
+public sealed record ApplicationResponse(
+    string Id,
+    string GrantCallId,
+    string IdeaId,
+    IReadOnlyDictionary<string, object?> Content,
+    string Status,
+    DateTimeOffset CreatedAt);

backend/Application/Dtos/IdeaDtos.cs

@@ -0,0 +1,41 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace TarninaHub.Application.Dtos;
+
+public sealed record IdeaCardRequest(
+    string? Essence,
+    string? Audience,
+    string? Stage);
+
+public sealed record CreateIdeaRequest(
+    [Required, StringLength(200, MinimumLength = 3)] string Title,
+    [Required, StringLength(4000, MinimumLength = 10)] string Description,
+    IdeaCardRequest? Card);
+
+public sealed record UpdateIdeaRequest(
+    [Required, StringLength(200, MinimumLength = 3)] string Title,
+    [Required, StringLength(4000, MinimumLength = 10)] string Description,
+    string? Status);
+
+public sealed record IdeaCardResponse(
+    string Id,
+    string IdeaId,
+    string Essence,
+    string Audience,
+    string Stage);
+
+public sealed record IdeaResponse(
+    string Id,
+    string Title,
+    string Description,
+    string AuthorId,
+    string Status,
+    IdeaCardResponse? Card,
+    DateTimeOffset? UpdatedAt);
+
+public sealed record IdeaAssistRequest(string? Focus);
+
+public sealed record IdeaAssistResponse(
+    IReadOnlyList<string> Suggestions,
+    string ImprovedDescription,
+    bool FromLlm);

backend/Application/Mappings/IdeaStatusWire.cs

@@ -0,0 +1,26 @@
+using TarninaHub.Domain.Enums;
+
+namespace TarninaHub.Application.Mappings;
+
+public static class IdeaStatusWire
+{
+    public static string ToWire(this IdeaStatus status) => status switch
+    {
+        IdeaStatus.Draft => "draft",
+        IdeaStatus.Submitted => "submitted",
+        IdeaStatus.InReview => "in_review",
+        IdeaStatus.Accepted => "accepted",
+        IdeaStatus.Rejected => "rejected",
+        _ => throw new ArgumentOutOfRangeException(nameof(status), status, null),
+    };
+
+    public static IdeaStatus? Parse(string? value) => value switch
+    {
+        "draft" => IdeaStatus.Draft,
+        "submitted" => IdeaStatus.Submitted,
+        "in_review" => IdeaStatus.InReview,
+        "accepted" => IdeaStatus.Accepted,
+        "rejected" => IdeaStatus.Rejected,
+        _ => null,
+    };
+}