feat(swift): generate Version.swift with sdkVersion constant (#14724)

* feat(swift-sdk): generate Version.swift with SDK version constant

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* fix(swift-sdk): use minor version bump 0.31.0 for feat changelog entry

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* fix(swift-sdk): make sdkVersion public and add seed test snapshots

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

Author: Swimburger

generators/swift/sdk/src/SdkGeneratorCli.ts

@@ -172,6 +172,7 @@ export class SdkGeneratorCLI extends AbstractSwiftGeneratorCli<SdkCustomConfigSc
         this.generateSourceSchemaFiles(context);
         this.generateSourceRootClientFile(context);
         this.generateSourceEnvironmentFile(context);
+        this.generateVersionFile(context);
     }
 
     private async generateSourceAsIsFiles(context: SdkGeneratorContext): Promise<void> {
@@ -576,6 +577,18 @@ export class SdkGeneratorCLI extends AbstractSwiftGeneratorCli<SdkCustomConfigSc
         });
     }
 
+    private generateVersionFile(context: SdkGeneratorContext): void {
+        const spmDetails = context.getSPMDetails();
+        const version = spmDetails.minVersion;
+        if (version != null) {
+            context.project.addSourceAsIsFile({
+                nameCandidateWithoutExtension: "Version",
+                directory: RelativeFilePath.of(""),
+                contents: `public let sdkVersion = "${version}"\n`
+            });
+        }
+    }
+
     private generateSourceEnvironmentFile(context: SdkGeneratorContext): void {
         if (context.ir.environments && context.ir.environments.environments.type === "singleBaseUrl") {
             const environmentSymbol = context.project.nameRegistry.getEnvironmentSymbolOrThrow();

generators/swift/sdk/versions.yml

@@ -1,5 +1,16 @@
 # yaml-language-server: $schema=../../../fern-versions-yml.schema.json
 
+- version: 0.31.0
+  changelogEntry:
+    - summary: |
+        Generate a `Version.swift` source file containing the SDK version
+        string. This embeds the version in the generated source code for
+        consistency with other generators and fixes auto-versioning for
+        Swift SDKs.
+      type: feat
+  createdAt: "2026-04-07"
+  irVersion: 61
+
 - version: 0.30.0
   changelogEntry:
     - summary: |