Add Knowledge Hub books FTS and remove training UI (0.16.0).

Index Assistent/books search.jsonl, expose knowledge hops/catalog in chat, and drop QLoRA/HF training stack.

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

AssistentMemory.cs

@@ -144,14 +144,6 @@ public sealed partial class AssistentMemory : IDisposable
             Logs.Debug($"AssistentMemory store schema: {ex.Message}");
         }
         try
-        {
-            EnsureTrainingSchema();
-        }
-        catch (Exception ex)
-        {
-            Logs.Error($"AssistentMemory training schema failed: {ex.Message}");
-        }
-        try
         {
             EnsureUserPrefsSchema();
         }
@@ -193,17 +185,8 @@ public sealed partial class AssistentMemory : IDisposable
 
     internal void EnsureTrainingReady()
     {
+        // Training UI removed in 0.16 — heard examples live in memories only.
         EnsureOpen();
-        if (!HasTable("train_samples"))
-        {
-            EnsureTrainingSchema();
-        }
-        if (!HasTable("train_samples"))
-        {
-            throw new InvalidOperationException(
-                "Assistent training database unavailable (train_samples). "
-                + "Run gpu-rent seed-extensions and restart SwarmUI (≥0.15.6).");
-        }
     }
 
     void MigratePersonaColumn()
@@ -443,6 +426,7 @@ public sealed partial class AssistentMemory : IDisposable
         {
             TryIndexTags();
             TryIndexExamples();
+            TryIndexBooks();
             return;
         }
 
@@ -478,6 +462,7 @@ public sealed partial class AssistentMemory : IDisposable
             Logs.Debug($"AssistentMemory seed defer (embed unavailable): {ex.Message}");
             TryIndexTags();
             TryIndexExamples();
+            TryIndexBooks();
             return;
         }