feat: no silent drops

[dotkas]

Closes #97

[Copilot]

🟡 Changes recommended

The new $ref-sibling warning is skipped for PathItem contexts, which can leave ignored PathItem sibling keys without the intended “no silent drops” diagnostic.

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Pull request overview

This PR tightens generator diagnostics to avoid silently dropping spec/config content by adding pre-deserialization key/shape inspection, plus targeted runtime warnings for currently-ignored but valid OpenAPI features and translation limits.

Changes:

• Add an OpenAPI key/shape inspection pass (coverage) invoked by the loader for root and referenced documents, producing aggregated InvalidSpec errors and warnings.
• Add YAML config unknown-key diagnostics by comparing the input YAML tree against Config::default()’s serialized shape, emitting warnings while keeping parse errors unchanged.
• Expand lowering-time warnings for unsupported/ignored operation details (media-type selection, scalar parameter enum ignored, non-default parameter styles) and document the new behavior.

File summaries

File	Description
README.md	Updates the high-level behavior note to reflect “warn then ignore” for unknown config keys.
docs/design.md	Documents the new inspection/diagnostics model (errors vs warnings, pointers, referenced docs).
docs/configuration.md	Clarifies config compatibility: unknown keys warn (including nested sections) while invalid known values still error.
crates/oapi-codegen/tests/diagnostics_operations.rs	Adds integration tests asserting warnings don’t change generated output for various operation-level cases.
crates/oapi-codegen/tests/check_mode.rs	Adds tests for config unknown-key warnings, spec unknown-key failures, referenced-doc diagnostics, and JSON entry points.
crates/oapi-codegen/src/lower/schema.rs	Emits a warning when an Any schema is non-empty but must fall back to serde_json::Value.
crates/oapi-codegen/src/lower/paths.rs	Adds warnings for unsupported parameter styles, ignored scalar enums, and discarded/unsupported media types (including referenced origins).
crates/oapi-codegen/src/loader.rs	Invokes the new coverage::check on root and referenced documents before typed deserialization.
crates/oapi-codegen/src/lib.rs	Wires new internal modules (coverage, diagnostic) into the crate.
crates/oapi-codegen/src/error.rs	Introduces Error::InvalidSpec for unknown keys/invalid shapes and integrates it into Display/source.
crates/oapi-codegen/src/diagnostic.rs	Adds shared warning formatting and JSON-pointer escaping utility.
crates/oapi-codegen/src/coverage.rs	Implements the OpenAPI key catalogue, traversal, warning emission, and aggregated invalid-spec reporting.
crates/oapi-codegen/src/console.rs	Adds a CLI hint for InvalidSpec errors.
crates/oapi-codegen/src/config.rs	Adds config unknown-key warnings via untyped YAML inspection against the default serialized shape.

Review details

• Files reviewed: 14/14 changed files
• Comments generated: 1
• Review effort level: Lite

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[alchemax-housekeeper]

🎉 This PR is included in version 1.3.0-dev.1 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[alchemax-housekeeper]

🎉 This PR is included in version 1.3.0 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀