metal : per-device tuned (Q, NE) for flash-attn vec (#26570)

* metal : per-device tuned (Q, NE) for flash-attn vec (#25750)

* rebase Q-generic FA vec body from 01dc93607 (#23114)

* add 53 f16 (Q,NE) flash-attn vec instantiations (vec 80 -> 133)

* add FA vec (Q,NE) tuning table + dispatch wiring + SMEM cap fallback

* add  FA vec (Q,NE) perf sweep

* fill tuning result

* fold family table into a per-family representative SKU

* refactor tuning result format

* extend FA vec tuning to quantized KV caches

* sync fa vec tuner bucketing with runtime, use pointwise tuning regret

* update tuned table

* format and cleanup

* prefix fa_vec tuning procs with ggml_backend_metal_tuning_, drop unused fa_vec_override_active

* add device id -> token lookup for the offline tuning tool

* add ggml-metal-tuning skeleton

* add op-agnostic perf cell + median timing for the tuner

* add FA-vec graph build + tensor init to the tuner

* tools : add FA-vec (Q,NE) sweep, compression and table emit

* cool down and re-measure the dirty window on thermal drift

* test-backend-ops : replace the FA vec tune mode with a bounded (Q,NE) slice

* tools : document the Metal tuner, point the table comment at it

* abort on unknown KV type, single-source fa_vec_legal_ne

* cleanup

* honor -o in the FA vec (Q,NE) slice

* retune FA-vec (Q, NE) under a pointwise no-harm gate

* cont : add fa-vec tunings for M1 Pro, M2 Ultra, M5 Max

---------

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

ggml/src/ggml-metal/ggml-metal-device.h

@@ -207,6 +207,8 @@ struct ggml_metal_pipeline_with_params ggml_metal_library_get_pipeline_flash_att
         bool    has_bias,
         bool    has_scap,
         bool    has_kvpad,
+        int32_t nqpsg,
+        int32_t ne,
         int32_t nsg,
         int32_t nwg,
         bool    use_kv_f16,
@@ -257,6 +259,8 @@ enum ggml_metal_device_id {
     GGML_METAL_DEVICE_M5_ULTRA,
 };
 
+const char * ggml_metal_device_id_token(enum ggml_metal_device_id id);
+
 struct ggml_metal_device_props {
     int device;
     int device_phys;
@@ -279,6 +283,7 @@ struct ggml_metal_device_props {
     bool supports_gpu_family_apple7;
 
     enum ggml_metal_device_id device_id;
+    int gpu_family;
 
     int op_offload_min_batch_size;
 };