feat(GRO-1202): add sign-in/sign-up rate limit overrides

Port rate limit customRules from groombook/app PR #392 to groombook/api.
Adds per-route limits for /sign-in/social, /sign-in/email, and /sign-up/email
to both AUTH_DISABLED and production better-auth() instances.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/src/lib/auth.ts

@@ -97,6 +97,9 @@ export async function initAuth(): Promise<void> {
           window: 10,
           storage: "memory",
           customRules: {
+            "/sign-in/social": { max: 10, window: 60 },
+            "/sign-in/email": { max: 10, window: 60 },
+            "/sign-up/email": { max: 5, window: 60 },
             "/get-session": false,
           },
         },
@@ -247,6 +250,9 @@ export async function initAuth(): Promise<void> {
         window: 10,
         storage: "memory",
         customRules: {
+          "/sign-in/social": { max: 10, window: 60 },
+          "/sign-in/email": { max: 10, window: 60 },
+          "/sign-up/email": { max: 5, window: 60 },
           "/get-session": false,
         },
       },