feat: user auth, API keys, Stripe billing, and dashboard scoping

- NextAuth v5 credentials auth with registration/login pages
- API key CRUD (create, list, revoke) with secure hashing
- Stripe checkout, webhooks, and customer portal integration
- Rate limiting per subscription tier
- All dashboard API endpoints scoped to authenticated user
- Prisma schema: User, Account, Session, ApiKey, plus Stripe fields
- Auth middleware protecting dashboard and API routes

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-Claude)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

apps/web/src/app/docs/getting-started/page.tsx

@@ -40,7 +40,26 @@ export default function GettingStartedPage() {
             </a>
             )
           </li>
-          <li>An API key for authentication</li>
+          <li>
+            An AgentLens account —{" "}
+            <a
+              href="/register"
+              className="text-emerald-400 hover:underline"
+            >
+              sign up here
+            </a>{" "}
+            if you haven{"'"}t already
+          </li>
+          <li>
+            An API key (create one in{" "}
+            <a
+              href="/dashboard/keys"
+              className="text-emerald-400 hover:underline"
+            >
+              Dashboard &rarr; API Keys
+            </a>
+            )
+          </li>
         </ul>
       </section>
 
@@ -62,6 +81,23 @@ export default function GettingStartedPage() {
         <h2 className="text-2xl font-semibold mb-4">
           Step 2: Initialize AgentLens
         </h2>
+        <p className="text-neutral-400 leading-relaxed mb-4">
+          Sign up at{" "}
+          <a
+            href="https://agentlens.vectry.tech/register"
+            className="text-emerald-400 hover:underline"
+          >
+            agentlens.vectry.tech
+          </a>
+          , then go to{" "}
+          <a
+            href="/dashboard/keys"
+            className="text-emerald-400 hover:underline"
+          >
+            Dashboard &rarr; API Keys
+          </a>{" "}
+          to create your key. Pass it to the SDK during initialization:
+        </p>
 
         <h3 className="text-lg font-medium text-neutral-200 mb-2">Python</h3>
         <CodeBlock title="main.py" language="python">{`import agentlens