fix(v2): UX polish, spec compliance, type safety, race-condition fixes

- Auto-create WebhookToken for new users (first-user and admin-created),
  so setup wizard step 3 immediately has a valid secret to display
- Setup wizard: load webhook secret on step 3 entry (not only on AWS save),
  so skipping AWS setup still shows correct webhook info
- Admin panel: add Edit modal with username and password change for any user
  (spec: 'Edit username or password of any user')
- Webhook handler: only post 'no config' comment on opened/reopened actions,
  not on synchronize or closed — prevents spam on sync events
- deploy.ts: clear stale abort signal at start of runDeploy so a signal meant
  to cancel the previous job cannot accidentally abort the new one
- routes/auth.ts: fix sameSite cookie case to lowercase 'lax' per TypeScript
- Add node-cron type declaration to silence TS7016 for that import
- SPEC.md: fix ec2:ImportKeyPair → ec2:CreateKeyPair (code uses CreateKeyPair)
- example.env: improve comments, add NODE_ENV, add key generation hints

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

frontend/src/pages/SetupWizard.tsx

@@ -1,4 +1,4 @@
-import React, { useState } from "react";
+import React, { useState, useEffect } from "react";
 import { useNavigate } from "react-router-dom";
 import { api } from "../services/api";
 import { useAuth } from "../hooks/useAuth";
@@ -28,6 +28,18 @@ export function SetupWizard() {
   const [webhookUrl, setWebhookUrl] = useState("");
   const [webhookSecret, setWebhookSecret] = useState("");
 
+  // Auto-load webhook info whenever we reach step 3 (index 3 = "Your Webhook")
+  useEffect(() => {
+    if (step !== 3) return;
+    if (webhookSecret) return;
+    api.user.getWebhookSecret().then(res => {
+      if (res.ok && res.data) {
+        setWebhookUrl(`${window.location.origin}/webhook/${user?.id}`);
+        setWebhookSecret(res.data.token);
+      }
+    }).catch(() => {});
+  }, [step, user?.id]);
+
   const next = () => setStep(s => Math.min(s + 1, STEPS.length - 1));
   const skip = () => navigate("/");