docs: loud deprecation of badger v1 datastore

[lidel]

This is documentation-only change that applies more pressure to any remaining users of ancient badgerv1 backend.

Mainly opportunity to close old issues that no longer apply.

Details

badger v1 (go-ds-badger) has not been maintained by its upstream maintainers for years and has known bugs (startup timeouts, shutdown hangs, fd exhaustion). make the deprecation loud and unavoidable:

• print ERROR log line and bordered stderr message on every daemon start when a badger-based datastore is detected
• mark badgerds and badgerds-measure init profiles as DEPRECATED
• update docs/datastores.md and docs/config.md with migration guidance
• add changelog highlight for v0.40

badger v1 support will be removed later in 2026.

Demo

$ ipfs init --profile=badgerds                                                                                                                                                                                                                                                                  130 ...bo ?deprecate-badgerds
generating ED25519 keypair...done
peer identity: 12D3KooWCcPUc8fwAmV9e2sWgKvHXjaQiSwmXbnaNPeax3gFgLjq
initializing IPFS node at /tmp/claude/ipfs-wn8NnQdsfdsfsfd
2026-02-09T21:58:23.169+0100	ERROR	plugin/badgerds	badgerds/badgerds.go:114	badger v1 datastore is deprecated and will be removed later in 2026, migrate to flatfs or experimental pebbleds: https://github.com/ipfs/kubo/issues/11186

╔════════════════════════════════════════════════════════════════════════════╗
║                                                                            ║
║  ERROR: BADGER v1 DATASTORE IS DEPRECATED                                  ║
║                                                                            ║
║  This datastore is based on badger 1.x which has not been maintained       ║
║  by its upstream maintainers for years and has known bugs (startup         ║
║  timeouts, shutdown hangs, file descriptor exhaustion, and more).          ║
║                                                                            ║
║  Badger v1 support will be REMOVED later in 2026.                          ║
║                                                                            ║
║  To migrate:                                                               ║
║    1. Create a new IPFS_PATH with flatfs (or experimental pebbleds         ║
║       if flatfs does not serve your use case):                             ║
║         export IPFS_PATH=/path/to/new/repo                                 ║
║         ipfs init --profile=flatfs                                         ║
║    2. Move pinned data via ipfs dag export/import                          ║
║       or ipfs pin ls -t recursive|add                                      ║
║    3. Decommission the old badger-based node                               ║
║                                                                            ║
║  See https://github.com/ipfs/kubo/blob/master/docs/datastores.md           ║
║      https://github.com/ipfs/kubo/issues/11186                             ║
║                                                                            ║
╚════════════════════════════════════════════════════════════════════════════╝

References

• Part of Remove badger v1 datastore support #11186

Closes

• Closes Make badger-ds the default datastore #4279
• Closes GC is slower with badger (with syncwrites enabled) #4298
• Closes Document Badger's available options #5307
• Closes Unify Badger docs #5624
• Closes Make badger mmapping configurable #6449
• Closes Expose Badger compression options #6848
• Closes badgerds prints to terminal: Latest Entry Header in LSM Key #7131
• Closes IPFS startup with Badger Datastore is hitting the systemd-timeout #7273
• Closes Shutdown issue with badgerDS - keeps reading from the disk #7283
• Closes ipfs config execute badger things. #9519

[lidel]

Merging to include in 0.40.0-rc1 and get early feedback on #11186