perf(permissions): cache space role and page edit lookups (#2208)

apps/server/src/common/helpers/cache-keys.ts

@@ -1,3 +1,11 @@
 export const CacheKey = {
   LICENSE_VALID: (workspaceId: string) => `license:valid:${workspaceId}`,
+  SPACE_ROLES: (userId: string, spaceId: string) =>
+    `perm:space-roles:${userId}:${spaceId}`,
+  PAGE_CAN_EDIT: (userId: string, pageId: string) =>
+    `perm:can-edit:${userId}:${pageId}`,
 };
+
+// Permission caches dedupe repeated checks within and across short request bursts.
+// 5s keeps staleness on revocations bounded.
+export const PERMISSION_CACHE_TTL_MS = 5_000;