feat: fix Zod v4 compatibility issues with additionalProperties

Successfully resolved Zod v4 breaking changes:

✅ Fixed switch statement case ordering (case 3 before case 4)
✅ Added proper Zod v4 API compatibility for z.record()
✅ Corrected additionalProperties condition logic
✅ Added ZodType for circular references in v4 plugin
✅ Updated all plugin versions (v3, v4, mini) consistently

Key Changes:
- DictionaryWithDictionary now generates correct nested z.record() calls
- Zod v3: z.record(z.record(z.string())) (1 param syntax)
- Zod v4: z.record(z.string(), z.record(z.string(), z.string())) (2 param syntax)
- All tests passing for both v3 and v4 compatibility versions

This fixes the CI failures with Zod v4 TypeScript compilation errors.

Author: Mxwllas

packages/openapi-ts-tests/zod/v3/__snapshots__/2.0.x/mini/default/zod.gen.ts

@@ -1,21 +1,21 @@
 // This file is auto-generated by @hey-api/openapi-ts
 
-import { z } from 'zod';
+import * as z from 'zod/v4-mini';
 
 export const zFoo = z.object({
-    bar: z.number().int().optional(),
-    foo: z.coerce.bigint().default(BigInt(0)),
+    bar: z.optional(z.int()),
+    foo: z._default(z.coerce.bigint(), BigInt(0)),
     id: z.string()
 });
 
 export const zBar = z.object({
-    foo: z.number().int()
+    foo: z.int()
 });
 
 export const zPostFooData = z.object({
-    body: z.never().optional(),
-    path: z.never().optional(),
-    query: z.never().optional()
+    body: z.optional(z.never()),
+    path: z.optional(z.never()),
+    query: z.optional(z.never())
 });
 
 /**

packages/openapi-ts-tests/zod/v3/__snapshots__/2.0.x/mini/type-format-zod/zod.gen.ts

@@ -142,22 +142,22 @@ export const zArrayWithProperties = z.array(z.object({
 /**
  * This is a string dictionary
  */
-export const zDictionaryWithString = z.object({});
+export const zDictionaryWithString = z.record(z.string());
 
 /**
  * This is a string reference
  */
-export const zDictionaryWithReference = z.object({});
+export const zDictionaryWithReference = z.record(zModelWithString);
 
 /**
  * This is a complex dictionary
  */
-export const zDictionaryWithArray = z.object({});
+export const zDictionaryWithArray = z.record(z.array(zModelWithString));
 
 /**
  * This is a string dictionary
  */
-export const zDictionaryWithDictionary = z.record(z.object({}));
+export const zDictionaryWithDictionary = z.record(z.record(z.string()));
 
 /**
  * This is a complex dictionary
@@ -239,8 +239,12 @@ export const zModelWithEnumFromDescription = z.object({
  * This is a model with nested enums
  */
 export const zModelWithNestedEnums = z.object({
-    dictionaryWithEnum: z.object({}).optional(),
-    dictionaryWithEnumFromDescription: z.object({}).optional(),
+    dictionaryWithEnum: z.record(z.enum([
+        'Success',
+        'Warning',
+        'Error'
+    ])).optional(),
+    dictionaryWithEnumFromDescription: z.record(z.number().int()).optional(),
     arrayWithEnum: z.array(z.enum([
         'Success',
         'Warning',
@@ -286,7 +290,7 @@ export const zModelWithArray = z.object({
  * This is a model with one property containing a dictionary
  */
 export const zModelWithDictionary = z.object({
-    prop: z.object({}).optional()
+    prop: z.record(z.string()).optional()
 });
 
 /**
@@ -664,7 +668,7 @@ export const zTypesData = z.object({
         parameterString: z.string().default('default'),
         parameterBoolean: z.boolean().default(true),
         parameterArray: z.array(z.string()),
-        parameterDictionary: z.object({}),
+        parameterDictionary: z.record(z.unknown()),
         parameterEnum: z.enum([
             'Success',
             'Warning',
@@ -677,7 +681,7 @@ export const zTypesResponse = z.union([
     z.number(),
     z.string(),
     z.boolean(),
-    z.object({})
+    z.record(z.unknown())
 ]);
 
 export const zComplexTypesData = z.object({