v0.9.0: mongo: migrate MongoDB backend to Go driver v2

Changelog

• cc74dee docs(workflow): replace README guide with documentation link
• d523dc4 docs(natsjs): expand backend architecture warnings
• 4b133f9 docs(migrations): document BSON codec updates for MongoDB v2
• 572f797 docs: add v0.9 migration guide
• ef2d001 docs(mongo): add Go driver v2 migration guide
• bad7900 backend(mongod): Migrate MongoDB backend to driver v2
• 85dfb5d docs(natsjs): deprecate flawed JetStream backend
• 761e5d7 chore(deps): bump golang.org/x/crypto from 0.50.0 to 0.52.0
• f24b6ca chore(deps): bump github.com/jackc/pgx/v5 from 5.9.2 to 5.10.0
• 304bd02 chore(deps): bump google.golang.org/grpc from 1.80.0 to 1.82.1
• a708318 docs: update event store ui docs

goes-ui-v0.1.1..v0.9.0