fix(review): preserve generic gate warnings on the surface-close hold path (#10100)

applySurfaceGate's fourth merge path returned the surface evaluation
bare when the generic gate held with no blockers, dropping every
warning-carried hold reason (size, guardrail, secret-scan) instead of
unioning them like the three sibling paths already do.

Co-authored-by: bitfathers94 <237535319+bitfathers94@users.noreply.github.com>

Author: bitfathers94

src/review/content-lane-wire.ts

@@ -139,7 +139,7 @@ export function applySurfaceGate(
   if (generic.blockers.length === 0 && generic.conclusion === "success") return surface; // generic was clean → surface stands
   if (generic.blockers.length === 0) {
     if (surface.conclusion === "success") return generic;
-    return surface;
+    return { ...surface, warnings: [...generic.warnings, ...surface.warnings] };
   }
   // #3907: opt-in escape hatch from guard #3 below. Default (null/undefined/"advisory") preserves today's
   // behavior byte-identically. "gate" skips the override entirely, so an AI-judgment-only failure falls

test/unit/content-lane-wire.test.ts

@@ -92,14 +92,39 @@ describe("applySurfaceGate", () => {
 
     expect(applySurfaceGate(genericHold, surfaceMerge)).toBe(genericHold);
   });
-  it("lets a surface hard failure override a generic warning-only hold", () => {
-    const genericHold = gate({
-      conclusion: "neutral",
-      blockers: [],
-      warnings: [{ code: "oversized_pr", title: "Large change", severity: "warning", detail: "large" }],
-    });
+  it("lets a surface hard failure override a generic warning-only hold, preserving the generic gate's hold warnings", () => {
+    const oversizedPrFinding: AdvisoryFinding = { code: "oversized_pr", title: "Large change", severity: "warning", detail: "large" };
+    const genericHold = gate({ conclusion: "neutral", blockers: [], warnings: [oversizedPrFinding] });
+
+    const out = applySurfaceGate(genericHold, surfaceClose);
+    expect(out?.conclusion).toBe("failure");
+    expect(out?.blockers).toEqual(surfaceClose.blockers);
+    expect(out?.warnings).toEqual([oversizedPrFinding]);
+  });
+  it("the unchanged sub-case: a success generic with warnings still returns the surface verbatim", () => {
+    const genericSuccess = gate({ conclusion: "success", blockers: [], warnings: [{ code: "quality_readiness_low", title: "Readiness is low", severity: "warning", detail: "" }] });
+    expect(applySurfaceGate(genericSuccess, surfaceClose)).toBe(surfaceClose);
+  });
+  it("the unchanged sub-case: a holding generic against a success surface still returns the generic verbatim", () => {
+    const oversizedPrFinding: AdvisoryFinding = { code: "oversized_pr", title: "Large change", severity: "warning", detail: "large" };
+    const genericHold = gate({ conclusion: "neutral", blockers: [], warnings: [oversizedPrFinding] });
+    const surfaceMerge = gate({ conclusion: "success", title: "Surface", summary: "valid entry" });
+    expect(applySurfaceGate(genericHold, surfaceMerge)).toBe(genericHold);
+  });
+  it("REGRESSION (#10011): preserves the generic gate's hold warnings when a non-success surface verdict overrides it", () => {
+    const oversizedPrFinding: AdvisoryFinding = { code: "oversized_pr", title: "Large change", severity: "warning", detail: "large" };
+    const genericHold = gate({ conclusion: "neutral", blockers: [], warnings: [oversizedPrFinding] });
+
+    const manual = surfaceVerdictToGate({ verdict: "manual", summary: "auth declared" }).evaluation;
+    const outManual = applySurfaceGate(genericHold, manual);
+    expect(outManual?.conclusion).toBe("neutral");
+    expect(outManual?.warnings.map((w) => w.code)).toEqual(["oversized_pr", "surface_lane_manual"]);
 
-    expect(applySurfaceGate(genericHold, surfaceClose)).toBe(surfaceClose);
+    const close = surfaceVerdictToGate({ verdict: "close", summary: "bad entry" }).evaluation;
+    const outClose = applySurfaceGate(genericHold, close);
+    expect(outClose?.conclusion).toBe("failure");
+    expect(outClose?.blockers.map((b) => b.code)).toEqual(["surface_lane_reject"]);
+    expect(outClose?.warnings.map((w) => w.code)).toEqual(["oversized_pr"]);
   });
   it("PRESERVES a generic hard blocker over a surface merge (a committed secret can never merge)", () => {
     const secret: AdvisoryFinding = { code: "secret_leak", title: "Secret", severity: "critical", detail: "leaked key" };