Prepare v0.2.1 release

[aaltshuler]

Omnigraph v0.2.1

Omnigraph v0.2.1 is a focused follow-up release on top of v0.2.0. It adds query linting, improves query execution correctness, hardens the local RustFS bootstrap flow, and cleans up project config naming.

Highlights

Query lint and check

The CLI now ships a first-class query validation surface:

• omnigraph query lint
• omnigraph query check

These commands validate .gq files against either an explicit schema file or a local/S3-backed repo schema, emit structured results, and support both human-readable and JSON output.

Query execution fixes and aggregate support

This release includes several improvements in the query engine:

• aggregate execution support for read queries
• nullable query parameters now accept omission and explicit null for nullable params
• traversal planning and join alignment are more robust for traversal-introduced bindings

Together, these changes make complex read queries more dependable and easier to author.

Better local RustFS startup

The local RustFS bootstrap is more resilient:

• detects dirty/stale repo prefixes before blindly reinitializing
• makes bootstrap recovery clearer for persisted local RustFS state
• ships a more generic demo fixture instead of user-specific seed content

This reduces the most common failure mode in local-first setup.

Config terminology cleanup

omnigraph.yaml now uses graph-oriented naming:

• graphs: instead of targets:
• cli.graph / server.graph instead of target

This removes one of the more confusing overloaded terms in the CLI/server config model.

Included Changes

• PR Add query lint and check commands #15: query lint and query check commands
• PR Implement aggregate functions with GROUP BY support #6: aggregate execution support
• PR Add support for null literals in query parameters #3: nullable query parameter fixes
• PR Fix join alignment for traversal-introduced bindings #16: traversal planning and join-alignment fixes
• PR Harden local RustFS bootstrap repo recovery #13: local RustFS bootstrap recovery hardening
• PR Genericize bootstrap context fixture #14: generic bootstrap fixture
• PR Rename config targets to graphs #17: config rename from targets to graphs

Upgrade Notes

• If you maintain .gq files in-repo, add omnigraph query lint to your local validation workflow
• Existing configs must use graphs: / graph: after this release
• Local RustFS users should prefer the current bootstrap script from main or this release rather than older cached copies