refactor: externalize Sol-Attn and use public graph APIs

src/core/ggml_compat.h

@@ -0,0 +1,43 @@
+#ifndef __SD_CORE_GGML_COMPAT_H__
+#define __SD_CORE_GGML_COMPAT_H__
+
+#include "ggml-backend.h"
+
+#if __has_include("ggml-graph.h")
+#include "ggml-graph.h"
+#elif defined(SD_USE_UPSTREAM_GGML)
+#define SD_GGML_GRAPH_COMPAT
+
+int ggml_graph_n_leafs(const struct ggml_cgraph* graph);
+struct ggml_tensor* ggml_graph_leaf(const struct ggml_cgraph* graph, int index);
+// Like ggml_graph_add_node, appends metadata without traversing tensor dependencies.
+void ggml_graph_add_leaf(struct ggml_cgraph* graph, struct ggml_tensor* tensor);
+// Returns zero when the tensor has no recorded use count. Includes uses outside graph views.
+int32_t ggml_graph_use_count(const struct ggml_cgraph* graph, const struct ggml_tensor* tensor);
+
+typedef struct ggml_tensor* (*ggml_graph_tensor_map_fn)(const struct ggml_tensor* tensor, void* user_data);
+
+// Copies forward node/leaf order and recorded use counts, including external consumers.
+// The callback must be injective and may return NULL for dependencies outside the
+// node/leaf lists. It is called once per tensor in their dependency closure.
+// Tensor storage and edges are mapped by the caller.
+// The destination must have no gradients and enough capacity. Gradients are not copied.
+// Invalid mappings leave the destination unchanged. src and dst must be distinct.
+bool ggml_graph_cpy_mapped(const struct ggml_cgraph* src, struct ggml_cgraph* dst, ggml_graph_tensor_map_fn map, void* user_data);
+
+// Copies recorded counts for tensors in dst's node/leaf lists. Other metadata is unchanged.
+// This preserves external consumers when constructing an inference graph segment.
+bool ggml_graph_cpy_use_counts(const struct ggml_cgraph* src, struct ggml_cgraph* dst);
+
+// Executes nodes [first, last) with the original graph's use counts. No graph ownership
+// is transferred. Tensor storage must already be allocated; invalid bounds fail.
+enum ggml_status ggml_backend_graph_compute_async_range(ggml_backend_t backend,
+                                                        struct ggml_cgraph* graph,
+                                                        int first,
+                                                        int last);
+
+#else
+#error "Patched ggml requires ggml-graph.h; select SD_USE_UPSTREAM_GGML for upstream compatibility"
+#endif
+
+#endif