fix: remove expired device shares without sparse event arrays

[Toomad23]

Summary

Fixes #8044.

createDeviceShareLink removes expired entries with delete docs[i]. This leaves a sparse array; common.Clone() serializes the event through JSON, converting holes to null. The recipient's event.deviceShares loop then reads userid from null.

Use docs.splice(i--, 1) instead, preserving a dense array and checking the next entry after removal. Existing expiry boundary, recurring/unlimited-share behavior, field stripping, and per-recipient URL filtering are unchanged.

Verification (local harness, not part of the diff)

Per maintainer feedback, the regression harness is kept locally and is not included in this PR. It uses Node's built-in test runner with no extra dependencies. It executes the actual database callback and recipient loop extracted from meshuser.js, plus the actual common.Clone. Database and event transport are in-memory doubles.

node --check meshuser.js
git diff --check

Against upstream 029b7338ecfeeacc65da3b5a1a4cc069baeb2f65: 4 failures / 7 tests. After the fix: 7 / 7 passed.

Coverage: expired + live entries, consecutive expired entries, all expired, empty result, active/unlimited/recurring/boundary shares, owner versus other-recipient URL visibility, database-error path.

The local harness was re-run after removing the test directory; all checks still pass. The PR diff now contains only the one-line meshuser.js fix.

Scope and QA

• One production-line change; no UI, dependencies, configuration or schema changes.
• AI-assisted contribution prepared with Hermes; the changed control flow and test assertions were reviewed and the commands above were actually executed.
• These are source-level regression tests, not an end-to-end run with a live server/database/browser. No production system was changed.
• Opened as draft pending live integration/manual UI QA, in recognition of the repository's contribution checklist. Upstream CI status is not claimed here.

[si458]

Plz can to remove the tests folder

[Toomad23]

Removed the test directory as requested. The diff now contains only the one-line fix in meshuser.js. I kept the regression harness locally and re-ran it: 7/7 tests passed; node --check meshuser.js and git diff --check also pass. The PR description has been updated to make the verification scope clear.