Make sale hard deletion opt-in and super-admin-only

[sridharkalaibala]

Sale hard deletion is now an explicit, off-by-default setting under Core Settings > Sale. Only super admins can see or change the setting and delete sales; other roles are blocked by the API even if they hold ordinary sale-delete permission.

The tooltip explains that the sale leaves active Sales History and its data moves to Recycle Bin. Recycle Bin must be enabled, and deletion stops if the required backup cannot be saved. The setting is not copied between branches. Existing cancellation behavior is unchanged.

Also resolves the main release CodeQL alert in build-asset hashing by checking and reading the same open file descriptor.

Validation: targeted API, role/UI, translation, backup failure and cache tests passed; frontend assets built successfully. The full desktop run passed 4,169 tests and skipped five; its five failures were resolved by adding a missing role fixture and rerunning the timing-sensitive suites sequentially (30/30 passed). The only formatting failure was corrected and rechecked. Lint, docs, packaging and attribution passed. The extra parallel API run was interrupted after database timeouts; all three affected database suites passed sequential retries. The changed API suites passed 802 tests, with additional role/settings tests passing in subsequent runs.

[github-actions]

Merged to develop. Anyone can test this - you do not need write access.

Try it at https://develop.posnic.io, or run it yourself:

git fetch origin develop && git checkout develop
npm install && npm --prefix api install
npm run dev   # then http://localhost:3000

When you have tested it, say what you did and what happened, and set
QA passed or QA failed. If you cannot set labels, just comment -
a maintainer will.

Reporting that something is broken is as useful as fixing it. It is
better found here than by a shopkeeper.