chore: add DDP method audit and deprecation injector scripts

scripts/audit-ddp-methods.mjs walks the monorepo to enumerate every
Meteor.methods registration, find their callers across server/client/
ee, and cross-reference against REST endpoints registered in
apps/meteor/app/api/server. Produces docs/ddp-audit.{json,md} with
three buckets: used methods, orphans (no caller), and used methods
without a REST replacement.

scripts/add-ddp-deprecation.mjs consumes that audit and inserts
methodDeprecationLogger.method(name, '9.0.0', replacement) into the
body of every orphan and every used-method-with-REST-replacement,
adding the import in the relative-imports group. Skips methods that
already log a deprecation. Supports shorthand, colon-function, arrow,
and twoFactorRequired-wrapped registration shapes.

Author: ggazzo