feat(ci/cd): add coverage test

.gitea/workflows/test.yml

@@ -140,7 +140,21 @@ jobs:
         run: flutter analyze
 
       - name: Test
-        run: flutter test
+        run: flutter test --coverage
+
+      - name: Test coverage
+        run: |
+          awk -F: '
+            /^LF:/ { total += $2 }
+            /^LH:/ { covered += $2 }
+            END {
+              if (total == 0) {
+                print "Coverage: 0%"
+              } else {
+                printf "Coverage: %.2f%%\n", (covered / total) * 100
+              }
+            }
+          ' coverage/lcov.info
 
       - name: Build apk
         run: |