fix: simplify Codecov flag configuration and fix lint errors

- Remove paths filter from individual_flags (Go coverage uses full
  module paths like github.com/mpyw/sql-http-proxy/internal/...)
- Simplify CI flags from unit,go1.23 to just unit (avoid multi-flag
  complexity)
- Add verbose: true to codecov-action for debugging
- Fix errcheck and ineffassign lint errors in headers_test.go

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: mpyw

.github/workflows/ci.yml

@@ -36,14 +36,16 @@ jobs:
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: ./coverage-unit.txt
-          flags: unit,go${{ matrix.go-version }}
+          flags: unit
+          verbose: true
 
       - name: Upload e2e test coverage to Codecov
         uses: codecov/codecov-action@v5
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: ./coverage-e2e.txt
-          flags: e2e,go${{ matrix.go-version }}
+          flags: e2e
+          verbose: true
 
   lint:
     name: Lint

codecov.yml

@@ -14,12 +14,8 @@ flag_management:
     carryforward: true
   individual_flags:
     - name: unit
-      paths:
-        - internal/
       carryforward: true
     - name: e2e
-      paths:
-        - internal/
       carryforward: true
 
 comment:

internal/js/headers_test.go

@@ -204,12 +204,9 @@ func TestHeaders_ToJSObject(t *testing.T) {
 	require.NotNil(t, obj)
 
 	t.Run("get method", func(t *testing.T) {
-		result, err := vm.RunString(`
-			var headers = this.headers;
-			headers.get("Content-Type");
-		`)
-		_ = vm.Set("headers", obj)
-		result, err = vm.RunString(`headers.get("Content-Type")`)
+		err := vm.Set("headers", obj)
+		require.NoError(t, err)
+		result, err := vm.RunString(`headers.get("Content-Type")`)
 		require.NoError(t, err)
 		assert.Equal(t, "application/json", result.String())
 	})
@@ -265,8 +262,9 @@ func TestHeaders_ToJSObject(t *testing.T) {
 	})
 
 	t.Run("forEach method", func(t *testing.T) {
-		vm.Set("callCount", 0)
-		_, err := vm.RunString(`
+		err := vm.Set("callCount", 0)
+		require.NoError(t, err)
+		_, err = vm.RunString(`
 			headers.forEach(function(value, key) {
 				callCount++;
 			})

internal/server/server.go

@@ -118,4 +118,3 @@ func expandPathShorthands(path string) string {
 	}
 	return result.String()
 }
-