feat(disputed): Confirm My Validation button + discussion request modal

Backend: POST /tests/{id}/request-discussion
  - Only callable by the lead whose vote is 'approved' in a disputed test
  - Sends notification to the rejecting lead: 'Lead X confirms their
    approval and wants to discuss your rejection'
  - Logs the action in audit trail

Frontend:
- 'Confirm My Validation' button (amber outline) alongside 'Change to Rejected'
- Opens a modal showing:
    * Explanation: both leads must agree to finalise
    * Other lead's rejection reason/notes
    * What happens next (stays disputed, notification sent, either can change)
- 'Send Discussion Request' → calls the new endpoint → shows success state:
    'Lead username has been notified...'
- Instruction to reach out via team channels to resolve offline

Flow summary for disputed tests:
  Approving lead sees 2 options:
    a) 'Confirm My Validation' → modal → send request → other lead notified
    b) 'Change to Rejected' → validation modal → both agree to reject → rejected

backend/app/routers/tests.py

@@ -745,6 +745,97 @@ def sync_tempo(
     return {"results": results}
 
 
+# ---------------------------------------------------------------------------
+# POST /tests/{id}/request-discussion  —  disputed: confirm vote + notify other lead
+# ---------------------------------------------------------------------------
+
+
+@router.post("/{test_id}/request-discussion")
+def request_discussion(
+    test_id: uuid.UUID,
+    db: Session = Depends(get_db),
+    current_user: User = Depends(require_any_role("red_lead", "blue_lead")),
+):
+    """Called when the approving lead confirms their vote in a disputed test.
+
+    Sends a notification to the other lead (who rejected) asking them to
+    discuss and resolve the conflict.  The test remains in 'disputed' state.
+    """
+    from app.models.enums import TestState as ModelTestState
+    from app.models.user import User as UserModel
+    from app.services.notification_service import create_notification
+
+    test = crud_get_test_or_raise(db, test_id)
+
+    if test.state.value != "disputed":
+        from app.domain.errors import BusinessRuleViolation
+        raise BusinessRuleViolation("Test is not in disputed state")
+
+    role = current_user.role
+
+    # Identify who the "other lead" is (the one who rejected)
+    if role == "red_lead" and test.red_validation_status == "approved":
+        # Red approved, Blue rejected → notify Blue Lead who rejected
+        rejector_id = test.blue_validated_by
+        rejector_label = "Blue Lead"
+        requester_label = "Red Lead"
+    elif role == "blue_lead" and test.blue_validation_status == "approved":
+        # Blue approved, Red rejected → notify Red Lead who rejected
+        rejector_id = test.red_validated_by
+        rejector_label = "Red Lead"
+        requester_label = "Blue Lead"
+    else:
+        from app.domain.errors import BusinessRuleViolation
+        raise BusinessRuleViolation(
+            "You are not the approving lead in this conflict or the state is inconsistent"
+        )
+
+    # Look up the rejecting lead's username for the message
+    rejector = (
+        db.query(UserModel).filter(UserModel.id == rejector_id).first()
+        if rejector_id else None
+    )
+    rejector_name = rejector.username if rejector else rejector_label
+
+    # Notify the rejecting lead
+    if rejector_id:
+        try:
+            create_notification(
+                db,
+                user_id=rejector_id,
+                type="validation_conflict",
+                title="Discussion requested on disputed test",
+                message=(
+                    f"{requester_label} ({current_user.username}) is confirming their approval "
+                    f"of test '{test.name}' and wants to discuss your rejection with you. "
+                    f"Please reach out to resolve the disagreement."
+                ),
+                entity_type="test",
+                entity_id=str(test.id),
+            )
+        except Exception as e:
+            import logging
+            logging.getLogger(__name__).warning(
+                "Failed to send discussion notification: %s", e
+            )
+
+    log_action(
+        db,
+        user_id=current_user.id,
+        action="request_dispute_discussion",
+        entity_type="test",
+        entity_id=test.id,
+        details={"test_name": test.name, "rejector": rejector_name},
+    )
+    db.commit()
+
+    return {
+        "status": "notification_sent",
+        "message": f"Discussion request sent to {rejector_name}",
+        "rejector_username": rejector_name,
+    }
+
+
 # ---------------------------------------------------------------------------
 # POST /tests/import-rt  —  bulk import from a real Red Team engagement
 # ---------------------------------------------------------------------------

frontend/src/api/tests.ts

@@ -308,6 +308,16 @@ export interface RTImportResult {
   engagement: string;
 }
 
+/** Confirm approval in a disputed test and notify the rejecting lead to discuss. */
+export async function requestDiscussion(testId: string): Promise<{
+  status: string;
+  message: string;
+  rejector_username: string;
+}> {
+  const { data } = await client.post(`/tests/${testId}/request-discussion`);
+  return data;
+}
+
 /** Import results from a real Red Team engagement. */
 export async function importRT(payload: RTImportPayload): Promise<RTImportResult> {
   const { data } = await client.post<RTImportResult>("/tests/import-rt", payload);

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

@@ -1,3 +1,4 @@
+import { useState } from "react";
 import {
   FlaskConical,
   Play,
@@ -10,7 +11,11 @@ import {
   ShieldCheck,
   AlertTriangle,
   MessageSquare,
+  X,
+  UserCheck,
 } from "lucide-react";
+import { useMutation } from "@tanstack/react-query";
+import { requestDiscussion } from "../../api/tests";
 import type { Test, TestState, User } from "../../types/models";
 import LiveTimer from "./LiveTimer";
 
@@ -81,6 +86,13 @@ export default function TestDetailHeader({
 }: TestDetailHeaderProps) {
   const role = user?.role ?? "";
   const currentIdx = STATE_INDEX[test.state];
+  const [showDiscussModal, setShowDiscussModal] = useState(false);
+  const [discussResult, setDiscussResult] = useState<string | null>(null);
+
+  const discussMutation = useMutation({
+    mutationFn: () => requestDiscussion(test.id),
+    onSuccess: (data) => setDiscussResult(data.rejector_username),
+  });
 
   const formatDate = (d: string | null) => {
     if (!d) return null;
@@ -227,14 +239,24 @@ export default function TestDetailHeader({
         const side = role === "red_lead" ? "red" : role === "blue_lead" ? "blue" : null;
         if (side || role === "admin") {
           buttons.push(
-            <button
+            <div key="disputed-actions" className="flex items-center gap-2">
-              key="change-vote"
+              {/* Confirm keeping approval → open discussion modal */}
-              onClick={() => onOpenValidateModal(side ?? (test.red_validation_status === "approved" ? "red" : "blue"))}
+              <button
-              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"
+                onClick={() => { setShowDiscussModal(true); setDiscussResult(null); }}
-            >
+                className="flex items-center gap-1.5 rounded-lg border border-amber-500/40 bg-amber-500/10 px-4 py-2 text-sm font-medium text-amber-400 hover:bg-amber-500/20 transition-colors"
-              <XCircle className="h-4 w-4" />
+              >
-              Change Vote to Rejected
+                <UserCheck className="h-4 w-4" />
-            </button>,
+                Confirm My Validation
+              </button>
+              {/* Change vote to rejected */}
+              <button
+                onClick={() => onOpenValidateModal(side ?? (test.red_validation_status === "approved" ? "red" : "blue"))}
+                className="flex items-center gap-1.5 rounded-lg bg-red-700/80 px-4 py-2 text-sm font-medium text-white hover:bg-red-600 transition-colors"
+              >
+                <XCircle className="h-4 w-4" />
+                Change to Rejected
+              </button>
+            </div>,
           );
         }
       }
@@ -458,6 +480,108 @@ export default function TestDetailHeader({
           This test was rejected and needs to be reopened to restart the workflow.
         </div>
       )}
+
+      {/* Confirm My Validation — discussion request modal */}
+      {showDiscussModal && (
+        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 backdrop-blur-sm">
+          <div className="w-full max-w-lg rounded-xl border border-gray-700 bg-gray-900 shadow-2xl">
+            {/* Header */}
+            <div className="flex items-center justify-between border-b border-gray-800 px-6 py-4">
+              <div className="flex items-center gap-2">
+                <UserCheck className="h-5 w-5 text-amber-400" />
+                <h3 className="text-lg font-semibold text-white">Confirm Your Validation</h3>
+              </div>
+              <button onClick={() => { setShowDiscussModal(false); setDiscussResult(null); }}
+                className="rounded p-1 text-gray-400 hover:bg-gray-800 hover:text-white">
+                <X className="h-5 w-5" />
+              </button>
+            </div>
+
+            {!discussResult ? (
+              <div className="px-6 py-5 space-y-4">
+                {/* Conflict summary */}
+                <div className="rounded-lg border border-amber-500/20 bg-amber-500/5 p-4">
+                  <p className="text-sm font-medium text-amber-300 mb-2">
+                    ⚠ Both leads must agree before a test can be finalised
+                  </p>
+                  <p className="text-xs text-gray-400">
+                    You are confirming that your <strong className="text-white">approval is correct</strong> and
+                    that the other lead's rejection should be reviewed.
+                  </p>
+                </div>
+
+                {/* Other lead's rejection reason */}
+                {(test.red_validation_status === "rejected" && test.red_validation_notes) && (
+                  <div>
+                    <p className="mb-1 text-xs font-medium uppercase tracking-wider text-gray-500">Red Lead's rejection reason</p>
+                    <p className="rounded-lg border border-red-500/20 bg-red-900/10 p-3 text-sm italic text-gray-300">
+                      "{test.red_validation_notes}"
+                    </p>
+                  </div>
+                )}
+                {(test.blue_validation_status === "rejected" && test.blue_validation_notes) && (
+                  <div>
+                    <p className="mb-1 text-xs font-medium uppercase tracking-wider text-gray-500">Blue Lead's rejection reason</p>
+                    <p className="rounded-lg border border-red-500/20 bg-red-900/10 p-3 text-sm italic text-gray-300">
+                      "{test.blue_validation_notes}"
+                    </p>
+                  </div>
+                )}
+
+                {/* What happens next */}
+                <div className="rounded-lg border border-gray-700 bg-gray-800/50 p-4 space-y-2">
+                  <p className="text-xs font-semibold text-white">What happens when you send the discussion request:</p>
+                  <ul className="space-y-1 text-xs text-gray-400 list-disc list-inside">
+                    <li>The other lead receives a notification to contact you</li>
+                    <li>The test <strong className="text-white">remains in Disputed</strong> state</li>
+                    <li>Either lead can change their vote at any time to resolve it</li>
+                    <li>If both reject → test becomes Rejected; if both approve → Validated</li>
+                  </ul>
+                </div>
+
+                {discussMutation.isError && (
+                  <p className="text-sm text-red-400">Failed to send notification. Try again.</p>
+                )}
+              </div>
+            ) : (
+              /* Success state */
+              <div className="px-6 py-8 text-center space-y-3">
+                <CheckCircle className="mx-auto h-12 w-12 text-green-400" />
+                <p className="text-lg font-semibold text-white">Discussion request sent</p>
+                <p className="text-sm text-gray-400">
+                  <strong className="text-white">{discussResult}</strong> has been notified
+                  that you are standing by your approval and want to discuss their rejection.
+                </p>
+                <p className="text-xs text-gray-500">
+                  Reach out directly via your team's communication channels to resolve this.
+                </p>
+              </div>
+            )}
+
+            {/* Footer */}
+            <div className="flex justify-end gap-3 border-t border-gray-800 px-6 py-4">
+              <button
+                onClick={() => { setShowDiscussModal(false); setDiscussResult(null); }}
+                className="rounded-lg border border-gray-700 px-4 py-2 text-sm text-gray-400 hover:bg-gray-800"
+              >
+                {discussResult ? "Close" : "Cancel"}
+              </button>
+              {!discussResult && (
+                <button
+                  onClick={() => discussMutation.mutate()}
+                  disabled={discussMutation.isPending}
+                  className="flex items-center gap-2 rounded-lg bg-amber-600 px-4 py-2 text-sm font-medium text-white hover:bg-amber-500 disabled:opacity-50 transition-colors"
+                >
+                  {discussMutation.isPending
+                    ? <><Loader2 className="h-4 w-4 animate-spin" /> Sending…</>
+                    : <><MessageSquare className="h-4 w-4" /> Send Discussion Request</>
+                  }
+                </button>
+              )}
+            </div>
+          </div>
+        </div>
+      )}
     </div>
   );
 }