Add typed JSON output to theme push

[gonzaloriestra]

WHY are these changes introduced?

Related to https://github.com/shop/issues-develop/issues/23693

theme push has JSON output, but its result schema is not discoverable and execution chooses the final presentation. Strict checks and multiple environments can also produce several JSON documents on stdout.

WHAT is this pull request doing?

Add status: "success" when all upload operations succeed, or status: "failed" when any upload operation fails. A failed result can still contain a theme and partially uploaded files; the existing warning and error details remain available. Each environment has its own status.

Return typed transfer data and move final output into a validating codec and presenter. Keep compact JSON formatting, optional warnings/errors, terminal text, publish behavior, and the exported push() compatibility adapter. Progress and strict-check diagnostics use typed side events.

Normal output:

The theme 'MyTheme' (#1) was pushed successfully.

Matching JSON:

{
  "status": "success",
  "theme": {
    "id": 1,
    "name": "MyTheme",
    "role": "unpublished",
    "shop": "example.myshopify.com",
    "editor_url": "https://example.myshopify.com/admin/themes/1/editor",
    "preview_url": "https://example.myshopify.com?preview_theme_id=1"
  }
}

Draft contract for review: multiple environments produce one array in requested order. Each entry includes environment. Environments that throw, are skipped, or are cancelled are omitted; diagnostics go to stderr. Completed uploads with file errors remain in the array with status: "failed". No completed environment results produces []. Existing exit behavior stays unchanged, including partial and total environment failures. Single-environment cancellation still emits no success result.

The shared collector preserves store sequencing and waits for analytics cleanup before collecting successful results. JSON execution bypasses the terminal concurrency renderer to avoid escape sequences in stderr. The exported programmatic wrapper retains its existing strict-check output; the CLI uses side events.

Refresh the upload progress title when the upload finishes, so the completed event reports 100% even when the last polling update happened earlier.

How to manually test your changes?

pnpm shopify theme push --help
pnpm shopify theme push --json-schema
pnpm shopify theme push --store example.myshopify.com --theme MyTheme --unpublished --path ./theme --json
pnpm shopify theme push --store example.myshopify.com --theme MyTheme --unpublished --path ./theme --strict --json
pnpm shopify theme push --environment staging --environment production --force --json

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
• A single changeset for all theme migrations is added in the last PR, #8682.

[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;