Add prepared Business reporting API and desktop worker

[sridharkalaibala]

Business mobile reads need prepared, scoped amounts without running desktop reports on Cloud. This adds a bounded overview API and an asynchronous desktop worker, with version-2 sales definitions reconciled against the real sale writer. Discounts are not deducted twice; paid KOT bills count; older-bill returns belong to their return day.

Reads recheck current ACL, branch membership and publisher generation, and return unavailable rather than fabricated zeros. Desktop preparation has a lease, cancellation and work limits. Business sessions do not consume selling-handset slots; explicit IP blocks remain effective.

Owners with branch membership can explicitly replace the reporting desktop using live candidate presence, assignment generations and a durable audit journal. An opt-in Community desktop mode prepares and publishes locally without Cloud or a sync agent; the operator supplies secure HTTPS access. Neither mode silently steals another publisher's assignment.

Local validation: 17 real-Mongo auth/read/preparation/management tests, 82 metric/sale-writer tests, 52 desktop route/classification/handset checks, API lint/format, generated docs, declared dependencies and attribution passed. Crash recovery covers both Cloud publication and Community process restart. No CI jobs were added.

Stacked on #1003. Companion Gateway and mobile changes are required for Cloud; Community desktop deployment is documented separately. This remains draft pending large-history performance, source-completeness checkpoints and deployed/native qualification. Summaries are always labelled partial or delayed.

[sridharkalaibala]

The complete Business companion stack, including this change, is integrated into develop through #1023. All checks, including CodeQL, passed before merge. Closing this superseded stacked PR.