reasoning: stop answer fidelity guard blocking valid unclassified answers

lib/graph/apply-proposal.js

@@ -2689,6 +2689,70 @@ function normaliseSemanticText(value) {
     .trim();
 }
 
+function semanticContentTokens(value) {
+  const stopWords = new Set([
+    "the",
+    "and",
+    "for",
+    "that",
+    "this",
+    "with",
+    "from",
+    "into",
+    "than",
+    "then",
+    "they",
+    "them",
+    "their",
+    "there",
+    "about",
+    "would",
+    "could",
+    "should",
+    "because",
+    "being",
+    "been",
+    "have",
+    "has",
+    "had",
+    "were",
+    "what",
+    "when",
+    "where",
+    "which",
+    "while",
+    "mainly",
+    "roughly",
+    "specifically",
+    "directly",
+    "user",
+  ]);
+
+  return normaliseSemanticText(value)
+    .replace(/[^a-z0-9]+/g, " ")
+    .split(" ")
+    .filter((token) => token.length > 2 && !stopWords.has(token));
+}
+
+function semanticOverlapRatio(sourceText, candidateText) {
+  const source = new Set(semanticContentTokens(sourceText));
+  const candidate = new Set(semanticContentTokens(candidateText));
+
+  if (candidate.size === 0) return 1;
+
+  const overlap = [...candidate].filter((token) => source.has(token)).length;
+  return overlap / candidate.size;
+}
+
+function rawAnswerSupportsUnclassifiedMeaning(answer, userSupportedMeaning) {
+  const overlapRatio = semanticOverlapRatio(answer, userSupportedMeaning);
+  const overlappingTokens = semanticContentTokens(userSupportedMeaning).filter(
+    (token) => semanticContentTokens(answer).includes(token),
+  ).length;
+
+  return overlapRatio >= 0.4 || overlappingTokens >= 3;
+}
+
 function hasConditionalQualification(text) {
   const value = normaliseSemanticText(text);
   return (
@@ -2893,6 +2957,23 @@ function validateAnswerMeaningCompatibilityWithRawAnswer({ answer, proposal }) {
     }
   }
 
+  if (rawAnswerProfile.category === "other") {
+    if (supportedMeaningProfile.category !== "other") {
+      errors.push(
+        "answerMeaning.userSupportedMeaning introduces a stronger reasoning category than the raw answer establishes.",
+      );
+    } else if (
+      !rawAnswerSupportsUnclassifiedMeaning(
+        answer,
+        proposal.answerMeaning.userSupportedMeaning,
+      )
+    ) {
+      errors.push(
+        "answerMeaning.userSupportedMeaning introduces unsupported meaning beyond what the raw answer itself states.",
+      );
+    }
+  }
+
   return errors;
 }
 
@@ -2964,9 +3045,13 @@ function validateAnswerMeaningAlignment(proposal) {
   }
 
   if (supportCategory === "other") {
-    if (resolved || containsConstraintBoundaryLanguage(proposalText)) {
+    if (
+      resolved &&
+      containsConstraintBoundaryLanguage(proposalText) &&
+      !containsConstraintBoundaryLanguage(meaningText)
+    ) {
       errors.push(
-        "Proposal cannot resolve or strengthen answerMeaning that does not clearly establish one of the protected reasoning categories.",
+        "Proposal cannot resolve beyond an unclassified answer by introducing an unsupported constraint or preference/trade-off distinction.",
       );
     }
   }