Introduce `might_be_async` as a workspace dependency, add it to
`mingling_core`, and regenerate all Cargo.lock files accordingly.
Multiple examples and test packages also pick up a newly transitive
`equivalent` crate.

Use `quote` token stream matching instead of debug formatting
to detect variable references in `unnecessary_render_result_creation`,
fixing false positives from string-based matching.

generation

Introduce `metadata` and `mlint` subcommands, wire up `cargo_metadata`
for manifest analysis, and enable procedural macro support in editors

Add initial project structure for the mingling-cli scaffolding tool,
including Cargo manifest and entry point