library: vendors/kb_text_shape + vendors/file_utils; modules/ffi/stb_truetype.sx retired

kb_text_shape (v2.10, JimmyLefevre) had been LOST from the sx tree —
ffi/stb_truetype.sx referenced repo paths that no longer existed (and
nothing runs glyph_cache, so the dangling unit never fired). The
trimmed copy returns from the m3te project as a proper vendor:
curated c/kbts_api.h decls over the full upstream header, README with
provenance, and examples/1627 pinning context + font creation so the
unit compiles and runs in-suite. file_utils (in-house asset-read
helper with the Android AAssetManager hook) gets the same unit shape.

modules/ffi/stb_truetype.sx is gone: glyph_cache imports the three
vendored units (stb_truetype, kb_text_shape, file_utils) directly.

library/vendors/kb_text_shape/README.md

@@ -0,0 +1,22 @@
+# vendors/kb_text_shape — OpenType text shaping for sx programs
+
+- Version: **v2.10** (version history at the top of the header)
+- Source: <https://github.com/JimmyLefevre/kb> (`kb_text_shape.h`)
+- License: zlib-style permissive (see the header's license block)
+- Files: `c/kb/kb_text_shape.h` (the full upstream single-header,
+  ~30k lines), `c/kb_text_shape_impl.c` (defines
+  `KB_TEXT_SHAPE_IMPLEMENTATION` and includes it), and
+  `c/kbts_api.h` — a hand-curated MINIMAL declaration header carrying
+  only the bound surface, so decl synthesis never parses the full
+  upstream header.
+
+`#import "vendors/kb_text_shape/kb_text_shape.sx"` resolves through
+the stdlib search paths; the implementation compiles once per machine
+through sx's object cache. Shape contexts, fonts, runs, and glyphs are
+opaque pointers on the sx side (modules/ui/glyph_cache.sx is the
+reference consumer; `examples/1627-vendor-kbts-shape-context.sx` pins
+context + font creation in the sx suite).
+
+To upgrade: replace `c/kb/kb_text_shape.h` with a newer upstream copy,
+extend `c/kbts_api.h` if the bound surface grows, update this file,
+and rebuild (the object cache keys on source bytes).

library/vendors/kb_text_shape/c/kb_text_shape_impl.c

@@ -0,0 +1,2 @@
+#define KB_TEXT_SHAPE_IMPLEMENTATION
+#include "kb/kb_text_shape.h"

library/vendors/kb_text_shape/c/kbts_api.h

@@ -0,0 +1,15 @@
+// Minimal API declarations for SX import.
+// Only the functions/types we actually use — avoids parsing the full 30k-line header.
+
+typedef struct kbts_shape_context kbts_shape_context;
+typedef struct kbts_font kbts_font;
+
+kbts_shape_context *kbts_CreateShapeContext(void *Allocator, void *AllocatorData);
+void kbts_DestroyShapeContext(kbts_shape_context *Context);
+kbts_font *kbts_ShapePushFontFromMemory(kbts_shape_context *Context, void *Memory, int Size, int FontIndex);
+void kbts_GetFontInfo2(kbts_font *Font, void *Info);
+void kbts_ShapeBegin(kbts_shape_context *Context, unsigned int ParagraphDirection, unsigned int Language);
+void kbts_ShapeUtf8(kbts_shape_context *Context, const char *Utf8, int Length, unsigned int UserIdGenerationMode);
+void kbts_ShapeEnd(kbts_shape_context *Context);
+int kbts_ShapeRun(kbts_shape_context *Context, void *Run);
+int kbts_GlyphIteratorNext(void *It, void **Glyph);

library/vendors/kb_text_shape/kb_text_shape.sx

@@ -0,0 +1,18 @@
+// =====================================================================
+// vendors/kb_text_shape — Jimmy Lefevre's kb_text_shape (OpenType text
+// shaping) as a `#import c` unit (c/, see README.md for version +
+// provenance).
+//
+// `#import "vendors/kb_text_shape/kb_text_shape.sx"` gives any sx
+// program text shaping with no system dependency. The decls come from
+// c/kbts_api.h — a hand-curated MINIMAL declaration header covering
+// only the bound surface (the full upstream header is ~30k lines and
+// is included only by the implementation unit). Shape contexts, fonts,
+// runs, and glyphs are opaque pointers on the sx side; see
+// modules/ui/glyph_cache.sx for the reference consumer.
+// =====================================================================
+
+#import c {
+    #include "c/kbts_api.h";
+    #source  "c/kb_text_shape_impl.c";
+};