Add token expiration date to social media pages for managed accounts

Update schema and routes to include a `tokenExpiresAt` field, setting it to 60 days after creation for social media page tokens.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: ae4037a0-2a6f-4530-9bac-79b543286bda
Replit-Commit-Checkpoint-Type: intermediate_checkpoint
Replit-Commit-Event-Id: a818a1ee-3b1a-48f9-9639-24fc156db095
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shared/schema.ts

@@ -24,6 +24,7 @@ export const socialPages = pgTable("social_pages", {
   pageId: text("page_id").notNull(),
   pageName: text("page_name").notNull(),
   accessToken: text("access_token").notNull(),
+  tokenExpiresAt: timestamp("token_expires_at"),
   followersCount: integer("followers_count").default(0),
   isActive: text("is_active").notNull().default("true"),
   createdAt: timestamp("created_at").defaultNow(),