Unified configuration for the banshee SQL toolchain.

[BansheeConfig] is the single struct threaded through the formatter, linter, completion engine and the generic LSP. It deserializes from a banshee.toml file whose schema is deliberately decoupled from the internal types of each crate, so the file format can stay stable as internals evolve.

Example banshee.toml

[format]
style = "sqlstyle"
keyword-case = "upper"
max-width = 100

[lint]
enabled = true
exclude = ["AM01"]

[lint.rules.CP01]
severity = "warning"

[database]
url-env = "DATABASE_URL"
schema = "public"