fix(scoring): cap non-code explicit totals

src/scoring/preview.ts

@@ -298,15 +298,14 @@
   const ossEmissionShare = constant(constants, "OSS_EMISSION_SHARE", 0.9);
   const repoSlice = emissionShare * ossEmissionShare;
   const directPrSlice = repoSlice * (1 - issueDiscoveryShare);
   const issueDiscoverySlice = repoSlice * issueDiscoveryShare;
   const sourceTokenScore = nonNegative(input.sourceTokenScore);
   // TEST_FILE_CONTRIBUTION_WEIGHT (#808): upstream weights test-file tokens at 0.05× relative to source tokens.
-  // Applied only when totalTokenScore is not explicitly provided — an explicit caller total is honoured as-is.
   const testFileWeight = constant(constants, "TEST_FILE_CONTRIBUTION_WEIGHT", 0.05);
   const cappedNonCodeTokenScore = applyNonCodeLineCap(input, constants);
-  const totalTokenScore = nonNegative(
-    input.totalTokenScore ?? sourceTokenScore + testFileWeight * nonNegative(input.testTokenScore) + cappedNonCodeTokenScore,
-  );
+  const derivedTotalTokenScore = sourceTokenScore + testFileWeight * nonNegative(input.testTokenScore) + cappedNonCodeTokenScore;
+  const totalTokenScore =
+    input.totalTokenScore === undefined ? nonNegative(derivedTotalTokenScore) : applyNonCodeCapToTotal(input.totalTokenScore, input, cappedNonCodeTokenScore);
   const sourceLines = Math.max(1, nonNegative(input.sourceLines ?? sourceTokenScore));
   const fixedBaseScore = input.fixedBaseScore ?? config?.fixedBaseScore ?? undefined;
   const rawDensity = sourceTokenScore / sourceLines;
@@ -978,6 +977,17 @@
   return lines <= maxLines ? score : score * (maxLines / lines);
 }
 
+function applyNonCodeCapToTotal(
+  totalTokenScore: number,
+  input: Pick<ScorePreviewInput, "nonCodeTokenScore" | "nonCodeLines">,
+  cappedNonCodeTokenScore: number,
+): number {
+  const total = nonNegative(totalTokenScore);
+  const nonCodeTokenScore = nonNegative(input.nonCodeTokenScore);
+  if (nonCodeTokenScore <= 0 || cappedNonCodeTokenScore >= nonCodeTokenScore) return total;
+  return Math.max(0, total - (nonCodeTokenScore - cappedNonCodeTokenScore));
+}
+
 function constant(constants: Record<string, number>, key: string, fallback: number): number {
   const value = constants[key];
   return typeof value === "number" && Number.isFinite(value) ? value : fallback;

test/unit/scoring.test.ts

@@ -283,9 +283,28 @@
           openPrCount: 0,
           credibility: 1,
         },
       }).scoreEstimate.contributionBonus,
       5,
     );
+
+    const explicitTotalWithNonCode = buildScorePreview({
+      repo,
+      snapshot: {
+        ...snapshot,
+        constants: { ...snapshot.constants, MAX_LINES_SCORED_FOR_NON_CODE_EXT: 300, CONTRIBUTION_SCORE_FOR_FULL_BONUS: 1500, MAX_CONTRIBUTION_BONUS: 25 },
+      },
+      input: {
+        repoFullName: repo.fullName,
+        sourceTokenScore: 100,
+        totalTokenScore: 700,
+        nonCodeTokenScore: 600,
+        nonCodeLines: 600,
+        sourceLines: 100,
+        openPrCount: 0,
+        credibility: 1,
+      },
+    });
+    expect(explicitTotalWithNonCode.scoreEstimate.contributionBonus).toBeCloseTo(cappedNonCode.scoreEstimate.contributionBonus, 5);
   });
 
   it("detects the active model from fetched constants before default fallback constants", async () => {