fix(canvas): retry uncertain text inspection without replaying image generation

lib/canvas/layout-replace-text-lock.ts

@@ -50,6 +50,12 @@ export function parseLayoutReplaceTextCheck(text: string) {
     if (normalize(d.original) === normalize(d.result)) return [];
     return [`原文「${d.original}」，结果「${d.result}」`];
   });
+  // An uncertain or unexplained verdict is a verifier failure, not evidence
+  // of a bad generated image. Let the read-only fallback inspect it; never
+  // trigger another paid image generation based on an empty accusation.
+  if (value.uncertain || (!value.identical && !differences.length)) {
+    throw new Error("模版文案检查没有给出可确认的具体结论");
+  }
   return { passed: value.identical && !value.uncertain && !differences.length && value.confidence >= 0.8,
     confidence: value.confidence, differences: [...new Set(differences)].slice(0, 8).map(d => d.slice(0, 160)) };
 }

tests/integration/layout-replace-validation.test.ts

@@ -123,8 +123,8 @@ test("text verification refuses discount/price changes, uncertain reading and in
   const good = { identical: true, uncertain: false, confidence: .95, differences: [] };
   assert.equal(parseLayoutReplaceTextCheck(JSON.stringify(good)).passed, true);
   assert.equal(parseLayoutReplaceTextCheck(JSON.stringify({ ...good, passed: true, differences: ["8.7折变成6.7折"] })).passed, false);
-  assert.equal(parseLayoutReplaceTextCheck(JSON.stringify({ ...good, uncertain: true })).passed, false);
-  assert.equal(parseLayoutReplaceTextCheck(JSON.stringify({ ...good, identical: false })).passed, false);
+  assert.throws(() => parseLayoutReplaceTextCheck(JSON.stringify({ ...good, uncertain: true })));
+  assert.throws(() => parseLayoutReplaceTextCheck(JSON.stringify({ ...good, identical: false })));
   for (const value of ["null", "{}", JSON.stringify({ ...good, confidence: "0.95" }), JSON.stringify({ ...good, differences: [1] })]) {
     assert.throws(() => parseLayoutReplaceTextCheck(value));
   }
@@ -154,6 +154,11 @@ test("independently observed support types reject added legs without confusing t
   assert.throws(() => parseLayoutReplaceSupport('{"supportType":"maybe","confidence":0.95}'));
 });
 
+test("an unexplained or uncertain text verdict cannot trigger paid semantic regeneration", () => {
+  assert.throws(() => parseLayoutReplaceTextCheck(JSON.stringify({ identical: false, uncertain: false, confidence: .95, differences: [] })));
+  assert.throws(() => parseLayoutReplaceTextCheck(JSON.stringify({ identical: true, uncertain: true, confidence: .95, differences: [] })));
+});
+
 test("quality rejection covers identity, background direction, copy loss, collage and low confidence", () => {
   assert.equal(quality().passed, true);
   for (const changes of [{ sourceProductPreserved: false }, { templateLayoutPreserved: false },