fix(providers): wire the LinkedIn and Moltbook settings DTOs

validatePosts runs settings-DTO validation only when the provider
declares `dto`. LinkedinProvider and MoltbookProvider never did, so for
linkedin, linkedin-page (inherits from LinkedinProvider) and moltbook
that validation layer silently did not run: LinkedinDto and MoltbookDto
existed but were unwired, and any malformed or missing settings value
was accepted and stored.

The dashboard never hits this (its form validates client-side with the
same DTO classes), but the public API (POST /public/v1/posts,
PUT /public/v1/posts/:id/settings) and the agent/MCP tools share
validatePosts and were unprotected - an API caller's typo or an
LLM-guessed settings value was accepted with a 200. The cost surfaced
later instead: a moltbook post without submolt silently publishes to
the "general" community (provider falls back to it), and a truthy
non-boolean carousel value on LinkedIn fails at publish time on a post
the user was told was valid.

Declare `dto = LinkedinDto` on LinkedinProvider (LinkedinPageProvider
inherits it) and `dto = MoltbookDto` on MoltbookProvider, so bad values
are rejected at save time with a specific message (400 / {errors}).
Audited all providers: these were the only unwired settings DTOs.

Author: giladresisi

libraries/nestjs-libraries/src/integrations/social/linkedin.provider.ts

@@ -58,6 +58,7 @@ type LinkedinPendingData = {
 export class LinkedinProvider extends SocialAbstract implements SocialProvider {
   identifier = 'linkedin';
   name = 'LinkedIn';
+  dto = LinkedinDto;
   oneTimeToken = true;
 
   isBetweenSteps = false;

libraries/nestjs-libraries/src/integrations/social/moltbook.provider.ts

@@ -6,6 +6,7 @@ import {
 } from '@gitroom/nestjs-libraries/integrations/social/social.integrations.interface';
 import { makeId } from '@gitroom/nestjs-libraries/services/make.is';
 import { SocialAbstract } from '@gitroom/nestjs-libraries/integrations/social.abstract';
+import { MoltbookDto } from '@gitroom/nestjs-libraries/dtos/posts/providers-settings/moltbook.dto';
 import dayjs from 'dayjs';
 import { Integration } from '@prisma/client';
 
@@ -15,6 +16,7 @@ export class MoltbookProvider extends SocialAbstract implements SocialProvider {
   override maxConcurrentJob = 100; // Moltbook: 100 requests/minute
   identifier = 'moltbook';
   name = 'Moltbook';
+  dto = MoltbookDto;
   isBetweenSteps = false;
   scopes = [] as string[];
   isWeb3 = true;