fix(10.1): CR-01 answer a value that does not fit its column with a 422

lagoon.Fill now returns a *lagoon.FillTypeError naming the key when a
requested value cannot be stored in its column (a fraction, exponent or
overflow for an integer field, or a value of the wrong type). The admin
save path maps it to a validation_failed 422 on that field instead of a
500 CapabilityError; genuine capability failures keep the 500.

modules/cabana/crud_test.go

@@ -469,3 +469,86 @@ func crudBody(t *testing.T, raw string) map[string]any {
 	}
 	return body
 }
+
+type crudYearRow struct {
+	ID   uint   `gorm:"column:id;primaryKey"`
+	Name string `gorm:"column:name"`
+	Year *int   `gorm:"column:year"`
+}
+
+func (crudYearRow) TableName() string        { return "cabana_crud_year_rows" }
+func (crudYearRow) Fillable() []string       { return []string{"name", "year"} }
+func (crudYearRow) Rules() map[string]string { return map[string]string{"name": "required"} }
+
+// TestCRUDFillTypeIsValidation covers CR-01: a value lagoon.Fill cannot store
+// in its column (a fraction, an exponent or an overflow for an integer field,
+// or a value of the wrong type) is the admin's input, so create and update
+// answer 422 with a message on that field rather than a 500 capability error.
+func TestCRUDFillTypeIsValidation(t *testing.T) {
+	_, db := newListService(t)
+	if err := db.Migrator().DropTable(&crudYearRow{}); err != nil {
+		t.Fatal(err)
+	}
+	if err := db.AutoMigrate(&crudYearRow{}); err != nil {
+		t.Fatal(err)
+	}
+	fsys := crudFS()
+	fsys["models/record/fields.yaml"] = &fstest.MapFile{Data: []byte(`fields:
+    name:
+        label: Name
+        type: text
+        required: true
+    year:
+        label: Year
+        type: number
+`)}
+	reg, err := compileRegistry([]controllerRef{{
+		plugin: formPlugin{fsys: fsys},
+		ctl:    crudController{rec: func() any { return &crudYearRow{} }},
+	}})
+	if err != nil {
+		t.Fatalf("registry: %v", err)
+	}
+	cc, ok := reg.Get("acme.demo.records")
+	if !ok {
+		t.Fatal("compiled controller missing")
+	}
+	svc := CRUDService{DB: db}
+	ctx := context.Background()
+	count := func() int64 {
+		t.Helper()
+		var n int64
+		if err := db.Model(&crudYearRow{}).Count(&n).Error; err != nil {
+			t.Fatal(err)
+		}
+		return n
+	}
+
+	for _, raw := range []string{`{"name":"Ada","year":1977.5}`, `{"name":"Ada","year":1e21}`, `{"name":"Ada","year":99999999999999999999}`, `{"name":"Ada","year":"1977"}`} {
+		_, err := svc.Create(ctx, cc, RecordInput{Body: crudBody(t, raw)})
+		assertValidation(t, err, "year", "The year field has an invalid value.")
+		if n := count(); n != 0 {
+			t.Fatalf("%s: rows=%d, an invalid year persisted", raw, n)
+		}
+	}
+	_, err = svc.Create(ctx, cc, RecordInput{Body: crudBody(t, `{"name":true}`)})
+	assertValidation(t, err, "name", "The name field has an invalid value.")
+
+	rec, err := svc.Create(ctx, cc, RecordInput{Body: crudBody(t, `{"name":"Ada","year":1977}`)})
+	if err != nil || rec["year"] == nil {
+		t.Fatalf("create=%#v err=%v, want year 1977", rec, err)
+	}
+	var stored crudYearRow
+	if err := db.Where("name = ?", "Ada").Take(&stored).Error; err != nil {
+		t.Fatal(err)
+	}
+	_, err = svc.Update(ctx, cc, stored.ID, RecordInput{Body: crudBody(t, `{"year":1977.5}`)})
+	assertValidation(t, err, "year", "The year field has an invalid value.")
+	var after crudYearRow
+	if err := db.Take(&after, stored.ID).Error; err != nil {
+		t.Fatal(err)
+	}
+	if after.Year == nil || *after.Year != 1977 {
+		t.Fatalf("year after rejected update = %v, want 1977", after.Year)
+	}
+}