feat: implement semantic search, knowledge unit extraction, and visualization components

src/NexusReader.Web.Client/Services/WasmKnowledgeService.cs

@@ -29,6 +29,26 @@ public class WasmKnowledgeService : IKnowledgeService
         return await CallKnowledgeApiAsync("/api/knowledge/summary", text, cancellationToken);
     }
 
+    public async Task<Result<List<RelevantContext>>> GetRelevantContextAsync(string query, string tenantId, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            var response = await _httpClient.PostAsJsonAsync("/api/knowledge/relevant", new { query, tenantId }, cancellationToken);
+            if (response.IsSuccessStatusCode)
+            {
+                var context = await response.Content.ReadFromJsonAsync<List<RelevantContext>>(cancellationToken: cancellationToken);
+                return context != null ? Result.Ok(context) : Result.Fail("Failed to deserialize relevant context.");
+            }
+
+            var errorBody = await response.Content.ReadAsStringAsync(cancellationToken);
+            return Result.Fail($"Server error ({response.StatusCode}): {errorBody}");
+        }
+        catch (Exception ex)
+        {
+            return Result.Fail(new Error($"Network error: {ex.Message}").CausedBy(ex));
+        }
+    }
+
     private async Task<Result<KnowledgePacket>> CallKnowledgeApiAsync(string endpoint, string text, CancellationToken cancellationToken)
     {
         try