Fix broken chat: slim Exact prompt and restore JSON discipline.

Stop duplicating Exact into live context, tighten preview URL matching, force write_prompt on "поправь", and gate critique behind vision + a real JSON fence.

Co-authored-by: Cursor <cursoragent@cursor.com>

AssistentConfig.cs

@@ -315,6 +315,46 @@ public sealed class AssistentConfig
         return def;
     }
 
+    /// <summary>Exact KV for the system prompt: params tables only (facts stay short / in RAG).</summary>
+    public JObject LoadExactForPrompt(string personaId)
+    {
+        JObject full = LoadExact(personaId);
+        if (full is null || full.Count == 0)
+        {
+            return full ?? new JObject();
+        }
+        JObject slim = new();
+        foreach (string key in new[] { "generation", "profiles", "aspect_table" })
+        {
+            if (full[key] is not null)
+            {
+                slim[key] = full[key].DeepClone();
+            }
+        }
+        if (full["facts"] is JObject facts)
+        {
+            // Keep short pointers only — long prose bloats 7B context and kills JSON discipline.
+            JObject shortFacts = new();
+            foreach (JProperty prop in facts.Properties())
+            {
+                string text = prop.Value?.ToString() ?? "";
+                if (text.Length <= 160)
+                {
+                    shortFacts[prop.Name] = text;
+                }
+                else
+                {
+                    shortFacts[prop.Name] = text.Substring(0, 157) + "…";
+                }
+            }
+            if (shortFacts.Count > 0)
+            {
+                slim["facts"] = shortFacts;
+            }
+        }
+        return slim;
+    }
+
     public JObject LoadAssistant(string personaId) => MergeJsonLayers("assistant.json", LayerRoots(personaId));
 
     public JObject LoadUi(string personaId) => MergeJsonLayers("ui.json", LayerRoots(personaId));