* feat: add _meta to content blocks and embedded resources; update schemas
* feat: set default protocol version; add _meta to content blocks/resources; update schemas
* chore: format content.rs via rustfmt
* chore(protocol): keep LATEST at 2025-03-26 per review until full 2025-06-18 compliance
* feat(prompt): add constructors with optional meta for image and resource
- Keep text helper; meta is currently ignored for text until schema supports it.
* refactor(prompt): simplify constructors so meta is optional; remove duplicate non-meta variants
* fix: modify code comment about version
* refactor(prompt): rename meta parameters in new_resource function for clarity
* feat(model): add json schema generation support for all model types
This commit adds JSON Schema support for all model types by implementing
`schemars::JsonSchema` trait. The feature is gated behind the new
`schemars` feature flag. This enables automatic schema generation for
API documentation and validation purposes. Added tests to verify schema
generation for client and server JSON-RPC messages.
* fix(model): add manual json schema implementation for `NumberOrString`
This commit adds a manual implementation of `JsonSchema` trait for the
`NumberOrString` enum to properly represent its union type nature in
JSON Schema. The schema now correctly specifies that the type can be
either a number or a string using the `oneOf` validation keyword.
* fix(model): skip extensions field in json schema generation
The `Extensions` type was incorrectly included in JSON schema
generation, which could lead to confusing API documentation. This commit
adds `#[schemars(skip)]` attribute to all `extensions` fields in request
and notification structs, and removes the manual `JsonSchema`
implementation for the `Extensions` type since it's an internal
implementation detail that shouldn't be exposed in the schema.
1. Suppot revision 2025-03-26 data types
2. Support meta, progress tokne, and extensions in request/notification,
3. Remove `Message`, use `JsonRpcMessage` directly
