model : add control vector support where missing (#20653)

* Add control vector functions to qwen3.5 and qwen-next models

* Add missing cvec compatibility to the rest of the models

* Adjust comments and formatting

* cleanup

* whitespace

---------

Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>

src/models/plamo3.cpp

@@ -109,6 +109,8 @@ llm_build_plamo3<iswa>::llm_build_plamo3(const llama_model & model, const llm_gr
 
         cur = build_cvec(cur, il);
         cb(cur, "l_out", il);
+
+        // input for next layer
         inpL = cur;
     }