Tighten normalize_recipe output checks

Address review findings on the normalize_recipe skill:

- Ingredient order: an ingredient is out of order when its name has more
  of its words in another line than in its own, not merely when it
  shares no word with its own line. Swapping "olive oil" and
  "sesame oil" now fails validation and triggers the repair turn.
- Required fields: Ingredient and NormalizedRecipe decode through
  UnmarshalJSON that requires every schema field and rejects unknown
  ones; qty, unit and note may not be omitted or null. Such a reply
  fails to decode and triggers the repair turn.
- Zero total: a present JSON-LD TotalMinutes that is not positive is
  rejected by PromptInput before any model call, instead of falling
  back to the model's minutes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/ai/skills/normalize_recipe_test.go

@@ -246,6 +246,99 @@ func TestNormalizeRecipeUnrepairedFails(t *testing.T) {
 	}
 }
 
+// stirFry has two ingredient lines that share the word "oil".
+var stirFry = RecipeText{
+	Title:       "Vegetable Stir Fry",
+	Ingredients: []string{"2 tbsp olive oil", "1 tbsp sesame oil"},
+	Steps:       []string{"Stir-fry the vegetables in the olive oil, then finish with the sesame oil."},
+}
+
+const stirFryReply = `{"ingredients":[
+	{"name":"olive oil","qty":"2","unit":"tbsp","note":""},
+	{"name":"sesame oil","qty":"1","unit":"tbsp","note":""}],
+	"method":"stovetop","difficulty":"easy","minutes_total":15}`
+
+func TestNormalizeRecipeSwapSharingAWordRepaired(t *testing.T) {
+	swapped := `{"ingredients":[
+		{"name":"sesame oil","qty":"1","unit":"tbsp","note":""},
+		{"name":"olive oil","qty":"2","unit":"tbsp","note":""}],
+		"method":"stovetop","difficulty":"easy","minutes_total":15}`
+	var f llm.Fake
+	f.QueueGenerate(reply(swapped), reply(stirFryReply))
+	out, reqs, err := normalize(t, &f, stirFry, 2)
+	if err != nil {
+		t.Fatal(err)
+	}
+	assertOutput(t, out, NormalizedRecipe{
+		Ingredients: []Ingredient{
+			{Name: "olive oil", Qty: "2", Unit: "tbsp"},
+			{Name: "sesame oil", Qty: "1", Unit: "tbsp"},
+		},
+		Method:       "stovetop",
+		Difficulty:   "easy",
+		MinutesTotal: minutes(15),
+	})
+	for _, want := range []string{
+		`ingredient 1 "sesame oil" matches line 2 "1 tbsp sesame oil", not line 1 "2 tbsp olive oil"; keep the ingredients in line order`,
+		`ingredient 2 "olive oil" matches line 1 "2 tbsp olive oil", not line 2 "1 tbsp sesame oil"; keep the ingredients in line order`,
+	} {
+		if repair := reqs[1].Messages[2].Content; !strings.Contains(repair, want) {
+			t.Fatalf("repair message = %q, want it to contain %q", repair, want)
+		}
+	}
+}
+
+func TestNormalizeRecipeOmittedFieldRepaired(t *testing.T) {
+	for name, tc := range map[string]struct{ first, want string }{
+		"omitted qty": {
+			strings.Replace(stirFryReply, `"qty":"1",`, ``, 1),
+			`ingredient has no "qty" field; give every field the schema requires`,
+		},
+		"null note": {
+			strings.Replace(stirFryReply, `"tbsp","note":""}]`, `"tbsp","note":null}]`, 1),
+			`ingredient field "note" is null, which the schema does not allow`,
+		},
+		"omitted unit": {
+			strings.Replace(stirFryReply, `"unit":"tbsp",`, ``, 1),
+			`ingredient has no "unit" field; give every field the schema requires`,
+		},
+		"omitted minutes_total": {
+			strings.Replace(stirFryReply, `,"minutes_total":15`, ``, 1),
+			`output has no "minutes_total" field; give every field the schema requires`,
+		},
+		"unknown field": {
+			strings.Replace(stirFryReply, `"note":""}]`, `"note":"","brand":"x"}]`, 1),
+			`ingredient has unknown field "brand"`,
+		},
+	} {
+		t.Run(name, func(t *testing.T) {
+			if tc.first == stirFryReply {
+				t.Fatal("replacement did not change the reply")
+			}
+			var f llm.Fake
+			f.QueueGenerate(reply(tc.first), reply(stirFryReply))
+			_, reqs, err := normalize(t, &f, stirFry, 2)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if repair := reqs[1].Messages[2].Content; !strings.Contains(repair, tc.want) {
+				t.Fatalf("repair message = %q, want it to contain %q", repair, tc.want)
+			}
+		})
+	}
+}
+
+func TestNormalizeRecipeZeroTotalRejected(t *testing.T) {
+	in := garlicPasta
+	in.TotalMinutes = minutes(0)
+	var f llm.Fake
+	_, _, err := normalize(t, &f, in, 0)
+	want := "recipe total time is 0 minutes; a given total must be positive"
+	if err == nil || !strings.Contains(err.Error(), want) {
+		t.Fatalf("err = %v, want it to contain %q", err, want)
+	}
+}
+
 func TestValidate(t *testing.T) {
 	s := normalizeRecipe{in: RecipeText{
 		Title:       "Tomato soup",
@@ -274,6 +367,13 @@ func TestValidate(t *testing.T) {
 				`ingredient 2 "tomatoes" matches line 1 "4 ripe tomatoes", not line 2 "1 onion, diced"; keep the ingredients in line order`,
 			},
 		},
+		"swapped sharing a word": {
+			NormalizedRecipe{Ingredients: []Ingredient{{Name: "diced onion"}, {Name: "ripe tomato"}}, Method: "oven"},
+			[]string{
+				`ingredient 1 "diced onion" matches line 2 "1 onion, diced", not line 1 "4 ripe tomatoes"; keep the ingredients in line order`,
+				`ingredient 2 "ripe tomato" matches line 1 "4 ripe tomatoes", not line 2 "1 onion, diced"; keep the ingredients in line order`,
+			},
+		},
 		"too many and bad enums": {
 			NormalizedRecipe{
 				Ingredients:  []Ingredient{{Name: "tomato"}, {Name: "onion"}, {Name: ""}},
@@ -305,6 +405,7 @@ func TestPromptInputRejects(t *testing.T) {
 	}{
 		"no title":       {RecipeText{Title: " ", Ingredients: []string{"1 egg"}}, "recipe has no title"},
 		"no ingredients": {RecipeText{Title: "Egg"}, "recipe has no ingredient lines"},
+		"negative total": {RecipeText{Title: "Egg", Ingredients: []string{"1 egg"}, TotalMinutes: minutes(-5)}, "recipe total time is -5 minutes; a given total must be positive"},
 		"blank line":     {RecipeText{Title: "Egg", Ingredients: []string{"1 egg", "\t"}}, "ingredient line 2 is blank"},
 		"blank step":     {RecipeText{Title: "Egg", Ingredients: []string{"1 egg"}, Steps: []string{""}}, "step 1 is blank"},
 	} {