fix(model): reject malformed JSON-RPC messages with conflicting result and error fields (#1283) (#1287)

* fix(model): reject malformed JSON-RPC messages with conflicting result and error fields (#1283)

* fix(model): preserve Deserialize<'de> bounds for JsonRpcMessage

Keep the public Deserialize impl equivalent to the previous derive
(Deserialize<'de> bounds, Noti type param) so cargo public-api --deny
removed passes, while still rejecting conflicting result/error fields.

* fix(model): preserve borrowed JSON-RPC payload deserialization

Reject conflicting result/error shapes without forcing an owned
serde_json::Value intermediate for from_str/from_slice. Use serde_json's
RawValue newtype token so Deserialize<'de> payload types can keep
borrows into the original input, with an owned fallback for from_value.

Adds regression coverage for generic borrowed request/response payloads.

* fix(model): alias JsonRpcMessageVisitor PhantomData for clippy

Factor the PhantomData<fn() -> (Req, Resp, Noti)> marker into a type
alias so clippy::type_complexity no longer fails CI under -D warnings.

* fix(model): preserve JSON-RPC deserialization in untagged wrappers

* fix(model): use borrowing-compatible buffered message parsing

* fix(model): preserve public deserializer signature

* refactor(model): remove masked JSON-RPC shape errors

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Co-authored-by: ump45nose <>

Author: ump45nose