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, 25 insertions, 0 deletions

diff --git a/meson.options b/meson.options
new file mode 100644
index 0000000..27bc018
--- /dev/null
+++ b/meson.options
@@ -0,0 +1,25 @@
+option(
+  'arch_flag',
+  type: 'string',
+  value: '',
+  description: 'Compiler flag for the lowest instruction set, such as -march=x86-64-v3. Higher SIMD levels are picked at run time',
+)
+option(
+  'tests',
+  type: 'boolean',
+  value: true,
+  description: 'Build and register the term tests and benchmarks',
+)
+option(
+  'write_fuzz_seeds',
+  type: 'integer',
+  min: 1,
+  value: 1000,
+  description: 'Seed count for write-fuzz-test',
+)
+option(
+  'kitty_tests',
+  type: 'boolean',
+  value: false,
+  description: 'Build the Linux Kitty parser compatibility tests (use an unsanitized build)',
+)