kv-cache: fix restoring mismatched KV cache rotation by saving exact rotation metadata (#28498)

* kv-cache: save exact KV rotation metadata, reject restoring mismatched rotation

* tests : move the state rotation test to test-save-load-state

the test is now part of the save/load test matrix and runs against
every model under test, like the rest of the suite

it probes the KV cache type combinations supported by the model and
treats models that do not use attention rotation as passing vacuously

Assisted-by: pi:llama.cpp/Qwen3.8-27B

* cont : skip unsupported KV caches

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

include/llama.h

@@ -43,10 +43,10 @@
 #define LLAMA_FILE_MAGIC_GGSQ 0x67677371u // 'ggsq'
 
 #define LLAMA_SESSION_MAGIC   LLAMA_FILE_MAGIC_GGSN
-#define LLAMA_SESSION_VERSION 10
+#define LLAMA_SESSION_VERSION 11
 
 #define LLAMA_STATE_SEQ_MAGIC   LLAMA_FILE_MAGIC_GGSQ
-#define LLAMA_STATE_SEQ_VERSION 3
+#define LLAMA_STATE_SEQ_VERSION 4
 
 #ifdef __cplusplus
 extern "C" {