Add typed JSON output to theme metafields pull

[gonzaloriestra]

WHY are these changes introduced?

Metafield downloads need structured outcomes and discoverable JSON support.

WHAT is this pull request doing?

Return strict flattened definitions, absolute artifact paths and explicit success/partial/skipped/cancelled outcomes. Preserve the native owner-keyed metafields.json file, successful downloads and owner-type failures; include a minor changeset for newly added theme JSON flags.

The public output follows docs/cli/json-output.md; explicitly named environments use one {environments: [...]} object.

How to manually test your changes?

shopify theme metafields pull --store example.myshopify.com --json
shopify theme metafields pull --json-schema

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes
• I've considered analytics changes to measure impact
• The change is user-facing — I've identified the correct bump type (patch for bug fixes · minor for new features · major for breaking changes) and added a changeset with pnpm changeset add

[gonzaloriestra]

/snapit

[github-actions]

🫰✨ Thanks @gonzaloriestra! Your snapshot has been published to npm.

Built from 1383c235d98feab6510d78163e9acb08d90b2339. Workflow run.

Test the snapshot by installing your package globally:

pnpm i -g --@shopify:registry=https://registry.npmjs.org @shopify/cli@0.0.0-snapshot-20261008090341

Caution

After installing, validate the version by running shopify version in your terminal.
If the versions don't match, you might have multiple global instances installed.
Use which shopify to find out which one you are running and uninstall it.

[github-actions]

⚠️ Potential Breaking Changes Detected

This PR contains changes that may break the existing contract.

@shopify/dev_experience — this PR contains breaking changes that require coordination for the next major release.

📦 Major Version Changesets

The following changesets request a major version bump:

Changeset	Package
theme-check-json-contract.md	'@shopify/cli': major
theme-duplicate-json-contract.md	'@shopify/cli': major
theme-info-json-contract.md	'@shopify/cli': major
theme-list-json-contract.md	'@shopify/cli': major
theme-open-json-contract.md	'@shopify/cli': major
theme-preview-json-contract.md	'@shopify/cli': major
theme-profile-environments.md	'@shopify/cli': major
theme-push-json-contract.md	"@shopify/cli": major

[github-actions]

Differences in type declarations

We detected differences in the type declarations generated by Typescript for this branch compared to the baseline ('main' branch). Please, review them to ensure they are backward-compatible. Here are some important things to keep in mind:

• Some seemingly private modules might be re-exported through public modules.
• If the branch is behind main you might see odd diffs, rebase main into this branch.

New type declarations

We found no new type declarations in this PR

Existing type declarations

packages/cli-kit/dist/public/node/base-command.d.ts

@@ -35,6 +35,7 @@ declare abstract class BaseCommand extends Command {
         argv: string[];
     }>;
     protected environmentsFilename(): string | undefined;
+    protected validateNonTTYFlags(flags: FlagOutput): void;
     protected failMissingNonTTYFlags(flags: FlagOutput, requiredFlags: string[]): void;
     private failMissingNonTTYFlagRequirements;
     private applicableNonTTYFlagRequirements;

packages/cli-kit/dist/public/node/themes/theme-manager.d.ts

@@ -11,5 +11,12 @@ export declare abstract class ThemeManager {
     findOrCreate(name?: string, role?: Role): Promise<Theme>;
     fetch(name?: string, role?: Role): Promise<Theme | undefined>;
     generateThemeName(context: string): string;
-    create(themeRole?: Role, themeName?: string): Promise<Theme>;
+    create(themeRole?: Role, themeName?: string): Promise<{
+        createdAtRuntime: boolean;
+        id: number;
+        name: string;
+        processing: boolean;
+        role: string;
+        src?: string;
+    }>;
 }
\ No newline at end of file