feat(tests): disputed state + fix timestamps on reopen

1. New 'disputed' state — one lead approved, the other rejected:
   - Both approved → validated (unchanged)
   - Both rejected → rejected (unchanged)
   - One approves + one rejects → disputed (new)
   - DB: ALTER TYPE teststate ADD VALUE 'disputed'
   - Notification sent to the approving lead explaining the conflict
     with the rejection notes

2. Disputed UI in TestDetailHeader:
   - Amber banner showing conflict + rejection reason from notes
   - 'Change Vote to Rejected' button for the lead who approved
   - Validation indicators shown for disputed state too

3. Fix timestamps on reopen (rejected → draft):
   - Keep red_started_at, blue_started_at etc. as historical record
   - Only clear paused_at defensively
   - Timestamps naturally update when test is re-executed

4. disputed badge (amber) added to all badge color maps

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/components/AddTestToCampaignModal.tsx

@@ -26,6 +26,7 @@ const stateBadge: Record<TestState, string> = {
   in_review: "bg-blue-900/50 text-blue-400 border-blue-500/30",
   validated: "bg-green-900/50 text-green-400 border-green-500/30",
   rejected: "bg-red-900/50 text-red-400 border-red-500/30",
+  disputed: "bg-amber-900/50 text-amber-400 border-amber-500/30",
 };
 
 const SEVERITY_COLORS: Record<string, string> = {

frontend/src/components/test-detail/TestDetailHeader.tsx

@@ -8,6 +8,8 @@ import {
   Loader2,
   Shield,
   ShieldCheck,
+  AlertTriangle,
+  MessageSquare,
 } from "lucide-react";
 import type { Test, TestState, User } from "../../types/models";
 import LiveTimer from "./LiveTimer";
@@ -40,6 +42,7 @@ const STATE_BADGE: Record<TestState, string> = {
   in_review: "bg-blue-900/50 text-blue-400 border-blue-500/30",
   validated: "bg-green-900/50 text-green-400 border-green-500/30",
   rejected: "bg-red-900/50 text-red-400 border-red-500/30",
+  disputed: "bg-amber-900/50 text-amber-400 border-amber-500/30",
 };
 
 // ── Props ──────────────────────────────────────────────────────────
@@ -212,6 +215,30 @@ export default function TestDetailHeader({
       );
     }
 
+    // Disputed: the lead who approved can change their vote to rejected
+    if (test.state === "disputed") {
+      const canChangeVote =
+        (role === "red_lead" && test.red_validation_status === "approved") ||
+        (role === "blue_lead" && test.blue_validation_status === "approved") ||
+        role === "admin";
+
+      if (canChangeVote) {
+        const side = role === "red_lead" ? "red" : role === "blue_lead" ? "blue" : null;
+        if (side || role === "admin") {
+          buttons.push(
+            <button
+              key="change-vote"
+              onClick={() => onOpenValidateModal(side ?? (test.red_validation_status === "approved" ? "red" : "blue"))}
+              className="flex items-center gap-1.5 rounded-lg bg-amber-600 px-4 py-2 text-sm font-medium text-white hover:bg-amber-500 transition-colors"
+            >
+              <XCircle className="h-4 w-4" />
+              Change Vote to Rejected
+            </button>,
+          );
+        }
+      }
+    }
+
     // Leads/admin on rejected -> Reopen
     if (
       test.state === "rejected" &&
@@ -238,7 +265,7 @@ export default function TestDetailHeader({
   // ── Dual validation indicators ───────────────────────────────────
 
   const renderValidationIndicators = () => {
-    if (test.state !== "in_review" && test.state !== "validated" && test.state !== "rejected") {
+    if (!["in_review", "validated", "rejected", "disputed"].includes(test.state)) {
       return null;
     }
 
@@ -347,6 +374,31 @@ export default function TestDetailHeader({
         </div>
       </div>
 
+      {/* Disputed conflict banner */}
+      {test.state === "disputed" && (
+        <div className="mt-3 flex items-start gap-3 rounded-xl border border-amber-500/30 bg-amber-500/5 p-4">
+          <AlertTriangle className="mt-0.5 h-5 w-5 shrink-0 text-amber-400" />
+          <div className="flex-1 min-w-0">
+            <p className="text-sm font-semibold text-amber-300">
+              Validation Conflict — Leads Disagree
+            </p>
+            <p className="mt-0.5 text-xs text-amber-400/80">
+              One lead approved and the other rejected this test.
+              {test.red_validation_status === "rejected" && test.red_validation_notes && (
+                <> Red Lead's reason: <span className="italic">"{test.red_validation_notes}"</span></>
+              )}
+              {test.blue_validation_status === "rejected" && test.blue_validation_notes && (
+                <> Blue Lead's reason: <span className="italic">"{test.blue_validation_notes}"</span></>
+              )}
+            </p>
+            <p className="mt-1.5 text-[10px] text-amber-400/60 flex items-center gap-1">
+              <MessageSquare className="h-3 w-3" />
+              The lead who approved should review the rejection reason and either change their vote or discuss with the other lead to resolve the disagreement.
+            </p>
+          </div>
+        </div>
+      )}
+
       {/* Progress bar */}
       {test.state !== "rejected" && (
         <div className="pt-2">

frontend/src/pages/CampaignDetailPage.tsx

@@ -55,6 +55,7 @@ const testStateColors: Record<string, string> = {
   in_review: "bg-blue-900/50 text-blue-400 border-blue-500/30",
   validated: "bg-green-900/50 text-green-400 border-green-500/30",
   rejected: "bg-red-900/50 text-red-400 border-red-500/30",
+  disputed: "bg-amber-900/50 text-amber-400 border-amber-500/30",
 };
 
 export default function CampaignDetailPage() {

frontend/src/pages/DashboardPage.tsx

@@ -54,6 +54,7 @@ const testStateBadgeColors: Record<string, string> = {
   in_review: "bg-blue-900/50 text-blue-400 border-blue-500/30",
   validated: "bg-green-900/50 text-green-400 border-green-500/30",
   rejected: "bg-red-900/50 text-red-400 border-red-500/30",
+  disputed: "bg-amber-900/50 text-amber-400 border-amber-500/30",
 };
 
 const testStateLabels: Record<string, string> = {

frontend/src/pages/TechniqueDetailPage.tsx

@@ -45,6 +45,7 @@ const testStateBadgeColors: Record<TestState, string> = {
   in_review: "bg-blue-900/50 text-blue-400 border-blue-500/30",
   validated: "bg-green-900/50 text-green-400 border-green-500/30",
   rejected: "bg-red-900/50 text-red-400 border-red-500/30",
+  disputed: "bg-amber-900/50 text-amber-400 border-amber-500/30",
 };
 
 const testResultBadgeColors: Record<TestResult, string> = {

frontend/src/pages/TestsPage.tsx

@@ -32,6 +32,7 @@ const testStateBadgeColors: Record<TestState, string> = {
   in_review: "bg-blue-900/50 text-blue-400 border-blue-500/30",
   validated: "bg-green-900/50 text-green-400 border-green-500/30",
   rejected: "bg-red-900/50 text-red-400 border-red-500/30",
+  disputed: "bg-amber-900/50 text-amber-400 border-amber-500/30",
 };
 
 const testStateLabels: Record<TestState, string> = {
@@ -41,6 +42,7 @@ const testStateLabels: Record<TestState, string> = {
   in_review: "In Review",
   validated: "Validated",
   rejected: "Rejected",
+  disputed: "Disputed",
 };
 
 const ALL_STATES: TestState[] = [
@@ -50,6 +52,7 @@ const ALL_STATES: TestState[] = [
   "in_review",
   "validated",
   "rejected",
+  "disputed",
 ];
 
 /* ── Helper: which team "owns" the current state ────────────────────── */

frontend/src/types/models.ts

@@ -43,7 +43,8 @@ export type TestState =
   | "blue_evaluating"
   | "in_review"
   | "validated"
-  | "rejected";
+  | "rejected"
+  | "disputed";   // one lead approved, the other rejected — needs discussion
 
 export type TestResult = "detected" | "not_detected" | "partially_detected";