bootstrap: meson build, test harness, CI, conventions, README/AGENTS (et0)

Phase 0 (task et0): lays the build/test/CI/convention groundwork before any
feature code.

- meson.build: project ggaze C11 -Wall -Wextra; deps gtk4/glib/gio/libadwaita;
  feature options gegl/jxl/avif/heif (auto); generated ggaze-config.h with
  app id, version, GGAZE_HAVE_* feature flags.
- tests: GLib g_test harness with separate unit/integration suites
  (--suite unit / --suite integration); test_bootstrap sanity test proves
  the harness compiles and the config header is reachable; -Db_coverage=true
  coverage target wired.
- CI: .woodpecker/ci.yml three lanes (minimal, gegl, asan) with xvfb for the
  integration track and a coverage lane that warns until M10.
- conventions: .clang-format (3-space, 80-col, K&R, *-on-var, return type on
  its own line) + .editorconfig matching docs/coding-conventions.md; CI
  clang-format --dry-run -Werror gate.
- top-level README.md (humans) and AGENTS.md (agents) pointing into docs/.
- LICENSE (GPL-3.0-or-later), .gitignore, dir placeholders.

Acceptance: meson setup build && ninja -C build && meson test -C build green;
clang-format --dry-run --Werror clean.

1 files changed, 22 insertions, 0 deletions

diff --git a/tests/meson.build b/tests/meson.build
new file mode 100644
index 0000000..c0ec9fb
--- /dev/null
+++ b/tests/meson.build
@@ -0,0 +1,22 @@
+# ggaze tests — two tracks (see docs/IMPLEMENTATION.md "Two test tracks").
+#
+#   unit        plain-C module tests, no display needed (>=80% coverage gate,
+#               warn until M10 then fail).
+#   integration  cross-module flows with real temp dirs + offscreen GTK.
+#
+# Run one track:   meson test -C build --suite unit
+#                  meson test -C build --suite integration
+# Coverage:        meson setup -Db_coverage=true build
+#                  meson test -C build
+#                  ninja -C build coverage   (needs lcov + genhtml)
+
+test_bootstrap = executable(
+   'test_bootstrap',
+   ['test_bootstrap.c', ggaze_conf_h],
+   include_directories : inc,
+   dependencies : [glib_dep],
+   install : false,
+)
+test('bootstrap', test_bootstrap, suite : 'unit')
+
+subdir('integration')
\ No newline at end of file