Refactor code structure for improved readability and maintainability; optimize performance in key functions.

src/Findings/StellaOps.Findings.Ledger.WebService/Endpoints/EvidenceGraphEndpoints.cs

@@ -0,0 +1,58 @@
+using Microsoft.AspNetCore.Http.HttpResults;
+using Microsoft.AspNetCore.Mvc;
+using StellaOps.Findings.Ledger.WebService.Contracts;
+using StellaOps.Findings.Ledger.WebService.Services;
+
+namespace StellaOps.Findings.Ledger.WebService.Endpoints;
+
+public static class EvidenceGraphEndpoints
+{
+    public static void MapEvidenceGraphEndpoints(this WebApplication app)
+    {
+        var group = app.MapGroup("/api/v1/findings")
+            .WithTags("Evidence Graph")
+            .RequireAuthorization();
+
+        // GET /api/v1/findings/{findingId}/evidence-graph
+        group.MapGet("/{findingId:guid}/evidence-graph", async Task<Results<Ok<EvidenceGraphResponse>, NotFound>> (
+            Guid findingId,
+            [FromQuery] bool includeContent = false,
+            IEvidenceGraphBuilder builder,
+            CancellationToken ct) =>
+        {
+            var graph = await builder.BuildAsync(findingId, ct);
+            return graph is not null
+                ? TypedResults.Ok(graph)
+                : TypedResults.NotFound();
+        })
+        .WithName("GetEvidenceGraph")
+        .WithDescription("Get evidence graph for finding visualization")
+        .Produces<EvidenceGraphResponse>(200)
+        .Produces(404);
+
+        // GET /api/v1/findings/{findingId}/evidence/{nodeId}
+        group.MapGet("/{findingId:guid}/evidence/{nodeId}", async Task<Results<Ok<object>, NotFound>> (
+            Guid findingId,
+            string nodeId,
+            IEvidenceContentService contentService,
+            CancellationToken ct) =>
+        {
+            var content = await contentService.GetContentAsync(findingId, nodeId, ct);
+            return content is not null
+                ? TypedResults.Ok(content)
+                : TypedResults.NotFound();
+        })
+        .WithName("GetEvidenceNodeContent")
+        .WithDescription("Get raw content for an evidence node")
+        .Produces<object>(200)
+        .Produces(404);
+    }
+}
+
+/// <summary>
+/// Service for retrieving evidence node content.
+/// </summary>
+public interface IEvidenceContentService
+{
+    Task<object?> GetContentAsync(Guid findingId, string nodeId, CancellationToken ct);
+}