audit: harden better-auth config, fix types, cleanup

- Fix email verification link using Better Auth's url parameter (was hardcoded to google.com)
- Make App.Locals session/user types nullable to match reality
- Add explicit rate limiting config (60s window, 100 max)
- Add trusted origins for localhost:5173 and production domain
- Add Forgot Password? and Register links to login page
- Remove unused dead code from auth-client.ts
- Remove outdated known-bug note from AGENTS.md (register redirect is fixed)

AGENTS.md

@@ -31,7 +31,6 @@ Requires `.env` with at least `DATABASE_URL`, `BETTER_AUTH_SECRET`, `BETTER_AUTH
 - **`expect: { requireAssertions: true }`** — every test must assert something.
 - **All route tests mock `$lib/db`** (Prisma client) and `$lib/auth-client`/`$lib/auth` via `vi.mock()`. Stub factories in `src/lib/test-utils.ts`.
 - **No `.env.test`** — mocking `$lib/db` makes real DB unnecessary.
-- **Known bug**: register page `throw redirect()` is caught by try/catch and returns 400 instead of redirecting (documented in test).
 
 ## Architecture notes
 

src/app.d.ts

@@ -3,8 +3,8 @@ import type { Session, User } from "better-auth";
 declare global {
 	namespace App {
 		interface Locals {
-			session: Session,
-			user: User,
+			session: Session | null;
+			user: User | null;
 		}
 	}
 }

src/lib/auth-client.ts

@@ -1,9 +1,3 @@
 import { createAuthClient } from "better-auth/svelte"
 
 export const authClient = createAuthClient({});
-
-const signIn = async () => {
-    const data = await authClient.signIn.social({
-        provider: "google",
-    });
-};

src/lib/auth.ts

@@ -11,13 +11,13 @@ export const auth = betterAuth({
 		provider: 'postgresql'
 	}),
 	emailVerification: {
-        sendVerificationEmail: async ({ user }) => {
+		sendVerificationEmail: async ({ user, url }) => {
 			void sendMail({
 				to: user.email,
 				templateId: 'email-verification-email',
 				data: {
 					target_email_address: user.email,
-					verification_link: 'https://google.com'
+					verification_link: url
 				}
 			});
 		}
@@ -43,5 +43,14 @@ export const auth = betterAuth({
 			clientSecret: process.env.GOOGLE_CLIENT_SECRET as string
 		}
 	},
+	rateLimit: {
+		enabled: true,
+		window: 60,
+		max: 100
+	},
+	trustedOrigins: [
+		'http://localhost:5173',
+		'https://portal.rhemawavetech.com'
+	],
 	plugins: [sveltekitCookies(getRequestEvent)]
 });

src/routes/login/+page.svelte

@@ -36,6 +36,14 @@
 			<input type="password" placeholder="Password" bind:value={password} required class="my-2" />
 			<button class="mt-4 rounded bg-blue-200 px-4 py-2" type="submit">Sign In</button>
 		</form>
+		<div class="mt-2 flex flex-col items-center gap-2">
+			<a href="/forgot-password" class="text-sm text-blue-600 hover:text-blue-800"
+				>Forgot Password?</a
+			>
+			<a href="/register" class="text-sm text-blue-600 hover:text-blue-800"
+				>Don't have an account? Register</a
+			>
+		</div>
 		<div class="mt-4 flex flex-col items-center justify-center">
 			<span>Or</span>
 			<button