feat: some more tests, a checkpoint

spec/test_render_spec.lua

@@ -0,0 +1,30 @@
+describe('cp.test_render', function()
+  local test_render = require('cp.test_render')
+
+  describe('get_status_info', function()
+    it('returns AC for pass status')
+    it('returns WA for fail status with non-zero code')
+    it('returns TLE for timeout status')
+    it('returns RTE for fail with zero code')
+    it('returns empty for pending status')
+  end)
+
+  describe('render_test_list', function()
+    it('renders test cases with CP terminology')
+    it('shows current test with > prefix')
+    it('displays input only for current test')
+    it('handles empty test cases')
+    it('preserves input line breaks')
+  end)
+
+  describe('render_status_bar', function()
+    it('formats time and exit code')
+    it('handles missing time')
+    it('handles missing exit code')
+    it('returns empty for nil test case')
+  end)
+
+  describe('setup_highlights', function()
+    it('sets up all highlight groups')
+  end)
+end)