Add CI pipeline and reusable test harness

A Gitea Actions workflow (.gitea/workflows/ci.yml) running the headless test
suite on push, plus shared test scaffolding: seeded-RNG / approx / tally helpers
(test_helpers.gd), a harness self-test, and a resolution + pseudo-locale
UI-layout robustness guard.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CCyaJPTHCH9EDthpf4A5Sj

run_tests.sh

@@ -8,12 +8,24 @@ SKIP_GAMEPLAY=0
 for arg in "$@"; do [[ "$arg" == "--no-gameplay" ]] && SKIP_GAMEPLAY=1; done
 
 echo "=== gdlint ==="
-gdlint *.gd levels/*.gd tests/*.gd
+gdlint actors systems ui props levels tests
+
+echo ""
+echo "=== Harness self-test (shared test_helpers: seeded RNG + approx + tally) ==="
+"$GODOT" --headless --script tests/harness_selftest.gd
 
 echo ""
 echo "=== Logic tests ==="
 "$GODOT" --headless --script tests/logic_test.gd
 
+echo ""
+echo "=== Damage pipeline (bull's hit reception through DamageEvent) ==="
+"$GODOT" --headless --script tests/damage_pipeline_test.gd
+
+echo ""
+echo "=== FX gallery smoke (every registered Fx effect spawns + frees) ==="
+"$GODOT" --headless --script tests/fx_gallery_test.gd
+
 echo ""
 echo "=== Console focus tests ==="
 "$GODOT" --headless --script tests/console_focus_test.gd
@@ -26,6 +38,10 @@ echo ""
 echo "=== Touch control tests (joystick self-heals, never strands) ==="
 "$GODOT" --headless --script tests/touch_controls_test.gd
 
+echo ""
+echo "=== UI layout tests (HUD stays on-screen, text fits, tap targets, scroll — across resolutions) ==="
+"$GODOT" --headless --script tests/ui_layout_test.gd
+
 echo ""
 echo "=== Rigid-skin tests (web mesh conversion keeps all materials) ==="
 "$GODOT" --headless --script tests/rigid_skin_test.gd