Introduce local store auth summary API

[dmerand]

Summary

Introduce a local auth summary API without changing shopify store list behavior yet.

Scope

• add StoredStoreAuthSummary
• add listStoredStoreAuthSummaries() under services/store/auth
• keep token-bearing session buckets as the current persistence source of truth
• keep conf traversal and bucket cleanup in session-store.ts
• re-export the summary API from services/store/auth/index.ts
• fix the stale store list command test assertion after the BP-only trim

Why this split exists

The next PR needs one narrow question answered first:

• what locally stored store auth exists on this machine?

This PR answers that without taking on product behavior:

• no --from store-auth
• no organization→store-auth fallback
• no persistence migration

That keeps the behavior PR focused on command policy and output, not on storage traversal.

Boundary this PR is trying to establish

• persistence details stay in session-store.ts
• callers see StoredStoreAuthSummary[]
• callers do not need token-bearing session buckets or conf layout knowledge

[dmerand]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Add store-auth source and auto fallback to store list #7714
• Introduce local store auth summary API #7709 👈 (View in Graphite)
• Add store list for organization stores #7708
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.

[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/common/string.d.ts

@@ -102,6 +102,16 @@ export declare function formatDate(date: Date): string;
  * @returns The transformed string in local system time.
  */
 export declare function formatLocalDate(dateString: string): string;
+/**
+ * Formats a date as a short calendar date like "May 22, 2026" () in UTC.
+ *
+ * UTC keeps the output deterministic regardless of the machine timezone. Returns an empty string
+ * when the value cannot be parsed into a valid date.
+ *
+ * @param value - A Date, epoch milliseconds, or a date string such as an ISO 8601 timestamp.
+ * @returns The formatted date, or an empty string when the value is invalid.
+ */
+export declare function formatShortDate(value: Date | number | string): string;
 /**
  * Given a list of items, it returns a string with the items joined by commas and the last item joined by "and".
  * All items are wrapped in double quotes.

packages/cli-kit/dist/public/common/url.d.ts

@@ -28,4 +28,13 @@ export declare function extractHost(value: string | null | undefined): string |
  * @param value - A URL or host string, possibly null/undefined.
  * @returns The myshopify subdomain handle, or undefined when the input isn't a  URL.
  */
-export declare function extractMyshopifyHandle(value: string | null | undefined): string | undefined;
\ No newline at end of file
+export declare function extractMyshopifyHandle(value: string | null | undefined): string | undefined;
+/**
+ * Extracts the leading subdomain label from a URL or host, across environments — e.g.
+ * , , or local development hosts — rather than assuming a
+ *  domain.
+ *
+ * @param value - A URL or host string, possibly null/undefined.
+ * @returns The first DNS label, or undefined when no host can be extracted.
+ */
+export declare function extractSubdomain(value: string | null | undefined): string | undefined;
\ No newline at end of file