Let META_PLATFORM_ORG_IDS limit the server's Meta app to some organizations - #1660

Summary

The server's Meta app (META_PLATFORM_*) gives the Instagram connector a one-click sign-in. While that app is in Development mode or in App Review, only its testers can finish the sign-in: on Cloud, customers started it 39 times in two days and none completed.

New optional variable META_PLATFORM_ORG_IDS (comma-separated organization ids). Empty or unset: nothing changes. With a list, the server's app is offered only to those organizations; every other organization sees the Instagram connector as on a server without an app: the setup page asks for an app of its own (or a pasted token), and POST /api/meta/connectors/:id/authorize answers with the variables to set. A connector with an app of its own is never affected.

Cloud and self-hosted behave the same; the variable is unset by default in both.

Changes

• meta-login.util.ts: metaPlatformAppOpenTo(organizationId); metaLoginAppOf takes the connector's organization id and skips the server's app when it is not open to it.
• meta-auth.controller.ts: GET /api/meta/platform answers for the caller's organization; authorize, complete and the account list pass the connector's organization.
• docker-compose.yml, docker-compose.cloud.yml, .env.example, docs/deployment.md (+ regenerated llms-full.txt).

No change in ee/. No schema change. The check uses req.user.organizationId and connector.organizationId, which the endpoints already compare.

Type

• Bug fix
• New feature
• Documentation
• Refactoring
• Performance improvement
• Other (describe below)

Testing

• Added/updated unit tests
• Tested manually (describe steps below)
• No tests needed (explain why)

packages/backend, after npm ci (root) and npx prisma generate:

• npx jest src/connectors/meta-auth src/connectors/engines/meta-login src/connectors/engines/bearer-token src/adapters/intl/instagram --maxWorkers=4: 6 suites passed; 82 tests passed, 3 skipped (live calls).
• npx tsc --noEmit -p tsconfig.json: no errors. npx eslint on the four files: clean.
• Root: node scripts/generate-llms-txt.mjs.

Checklist

• My code follows the existing code style
• I have tested my changes locally
• I have updated documentation (if applicable)
• All existing tests pass (npm test) (Meta suites locally, full suite in CI)
• This PR has a descriptive title

Related Issues

Follow-up to #1630.