feat: track parameter location (path/query/body) in IR

Add ParameterLocation type and `in` field to SchemaProperty so emitters
can distinguish query params from body params for proper URL construction.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: koriyoshi2041

src/parser/openapi-parser.ts

@@ -404,6 +404,7 @@ function extractRequestBodyProperties(
         type: prop.type?.toString() ?? "string",
         description: desc,
         required: isRequired,
+        in: "body",
         format: prop.format,
         enum: prop.enum as string[] | undefined,
         default: prop.default,
@@ -434,6 +435,7 @@ function extractRequestBodyProperties(
       type: schemaType,
       description: desc,
       required: isBodyRequired,
+      in: "body",
       format: schema.format,
       example: schema.example,
     });

src/types.ts

@@ -30,11 +30,14 @@ export interface AuthRequirement {
 
 // ─── Schema ──────────────────────────────────────────────
 
+export type ParameterLocation = "path" | "query" | "header" | "cookie" | "body";
+
 export interface SchemaProperty {
   readonly name: string;
   readonly type: string;
   readonly description: string;
   readonly required: boolean;
+  readonly in?: ParameterLocation;
   readonly format?: string;
   readonly enum?: readonly string[];
   readonly default?: unknown;