End-to-end regression test for GHSA-96q5-xm3p-7m84 / CVE-2026-35594: mints
a JWT for a link share via the real helper, then deletes the share row and
invokes the real ReadAllWeb handler to prove the full request path (not
just the unit-tested GetLinkShareFromClaims) surfaces the revocation.
Also fixes a pre-existing stale literal in the TestLinkSharing test fixture
struct: linkshareRead declared Hash="test1" while the actual fixture row
id=1 uses Hash="test". The old code never looked at the DB so the mismatch
went unnoticed; after the fix it would cause every link-share webtest that
used linkshareRead to fail hash validation.