Publish the first Microsoft Store release

## Problem

Microsoft's documented GitHub Actions update flow requires the app to be already published and live. Draft Omen therefore needs a complete first Partner Center submission before later releases can be automated.

## Proposed change

Complete the first submission interactively in Partner Center using the CI-produced `.msixupload` artifact. Supply the required pricing, availability, properties, age rating, package, Store listing, screenshots, and certification notes. Resolve package or policy failures and publish the certified app. Acquisition from the live Store remains a separate manual verification boundary because the documented GitHub-hosted update flow does not exercise the Microsoft Store client.

## Acceptance Criteria

- [ ] AC1: Pricing and availability, properties, age ratings, package settings, Store listing text, screenshots, logos, and certification notes are complete in Partner Center.
- [ ] AC2: Partner Center accepts and validates the exact `.msixupload` produced by the approved GitHub Actions run and the contained `.msix` matches its recorded checksum.
- [ ] AC3: The submission passes Microsoft security, technical, and content certification and reaches **In the Store** status with a Microsoft-signed package.
- [ ] AC4: The public Store listing has the intended name, publisher, description, images, supported device family, and acquisition settings.
- [ ] AC5: The publication record identifies the exact GitHub Actions run, package version and checksum, certification result, and public Store URL.
- [ ] AC6: Store acquisition is recorded as an external manual verification boundary for the final release-channel cutover, not as new hosted infrastructure in this ticket.

## Dependencies

Blocked by **Build and validate the MSIX package in GitHub Actions**.

## Implementation classification

- **Estimated size:** M
- **Orchestration risk:** High
- **Reason:** The first release crosses external account, listing, package-validation, certification, public-distribution, and hosted Windows verification boundaries.