fix(rpc): resolve lint warnings from review follow-up

- Drop the redundant eslint-disable on AnyProcedures; no-explicit-any
  is off repo-wide so the directive itself was the warning. Doc
  comment now explains why none is needed.
- Rename test's schema binding to _schema per the lint config's
  underscore-prefix rule for read-only-as-type bindings.

packages/rpc/src/types.ts

@@ -31,8 +31,9 @@ export interface ProcedureDef<Input = unknown, Output = unknown> {
  * A procedure map with its element types erased. The `any` is deliberate and
  * confined to this alias: the phantom `__input`/`__output` markers make
  * ProcedureDef invariant, so no narrower erasure accepts a real contract.
+ * (No eslint-disable needed — `no-explicit-any` is off repo-wide, and a
+ * redundant directive is itself a lint warning.)
  */
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
 export type AnyProcedures = Record<string, ProcedureDef<any, any>>;
 
 export interface ServiceContract<Procedures extends AnyProcedures = AnyProcedures> {