cherry-pick: make read txn timeout configurable and set default to 5min (conflicts → v5.0)

[github-actions]

Cherry-pick of PR #304 onto `v5.0` produced conflicts on commit(s): `f79e35fe56416ab51a42f2602c11dbca3c7b1282`.

Resolve the conflict markers on branch `cherry-pick/v5.0/pr-304` and merge this PR.

@claude please review branch `cherry-pick/v5.0/pr-304` and suggest a patch that resolves the conflict markers (<<<<<<< / ======= / >>>>>>>) introduced by cherry-picking PR #304 onto `v5.0`. Post the suggested patch as a comment here — do not push.

[Ethan-Arrowood]

Conflict resolution looks correct — the cherry-pick cleanly extracts the timeout loop into checkReadTxnTimeouts() and drives it from the new storage_maxReadTransactionOpenTime config (default 5min, down from the hardcoded 15min). The tick math lines up (20 ticks × 15s = 5min, and the log message reports 300s to match), the new config param is wired into hdbTerms.ts and imported in RecordEncoder.ts, and the unit tests cover both the expires-above and not-below-threshold cases. The done() idempotency guard is a nice touch too.

This is the intended payload of #304 already vetted on main, so I'm comfortable with it on v5.0.

One note: CI here is ~3 weeks stale and the one red check (Integration API Tests → not ok 4 - Delete records before, "Cannot read properties of undefined (reading 'status')") is the known job-system flake, unrelated to this change. Please kick a fresh CI run and merge once it's green.

Approving on that basis.

_{sent with Claude Opus 4.8}