term: move the term core to subprojects/term

The core now builds, tests, and benchmarks alone, as a Meson subproject
with no dependency on the main tree.

- include/term/ holds term.h and the header-only unicode/. src/ holds
  the core and its private headers. The main tree gets only
  include/term through term_dep, so it cannot reach a private header.
- The term tests, the term benchmarks, the Kitty parser suite, and
  tools/amalgamate.py and tools/generate_unicode.py move with it. The
  tests run as term:<name>.
- The main build passes its -march (arch_flag) and b_ndebug to the
  subproject. A directory configured before this commit needs
  meson configure -Dterm:arch_flag=-march=... once.
- The term tests compile with -UNDEBUG. They do work inside assert.
- The subproject exports term_test_dep with term_api.h, for the main
  tree's render, thumbnail, color, and selection tests.
- The Kitty bridge used struct vector2i and has not compiled since the
  public API redesign. It builds again. 2 of its 14 tests fail: REP
  after a tab, and a cursor report after a resize.
- dirgraph.py drops the term and unicode layers. Its self-test uses pty.
- The symbols test ignores the __odr_asan symbols that ASan adds.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/src/gstore.h b/src/gstore.h
new file mode 100644
index 0000000..0cedd30
--- /dev/null
+++ b/src/gstore.h
@@ -0,0 +1,36 @@
+#ifndef WSAP_TERM_GSTORE_H
+#define WSAP_TERM_GSTORE_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+struct gstore;
+struct term;
+
+/* Create a grapheme store for a terminal. */
+struct gstore *term_gstore_new(struct term *t);
+
+/* Free the grapheme store and its memory. */
+void term_gstore_free(struct gstore *g);
+
+/* Store a cluster of code points. Return its handle. */
+uint32_t term_gstore_intern(struct gstore *g, const uint32_t *cps, int n);
+
+/* Expand a handle to its code points. Return the count. */
+int term_gstore_expand(const struct gstore *g, uint32_t handle, uint32_t *cps, int cap);
+
+/* Mark reachable clusters and free unused ones. */
+void term_gstore_sweep(struct gstore *g, struct term *t);
+
+/* Mark one cluster handle as reachable. */
+void term_gstore_mark(struct gstore *g, uint32_t handle);
+
+/* Return the count of active clusters in the store. */
+uint32_t term_gstore_count(const struct gstore *g);
+
+/* Suppress automatic GC sweeps while temporary cell buffers hold handles. */
+void term_gstore_pin(struct gstore *g);
+void term_gstore_unpin(struct gstore *g);
+
+#endif