v1.36.275

Fix an intermittent Windows runtime-layout test failure: while an exclusive writer holds a lock, its heartbeat legitimately updates the lock owner's modification time. The read-only fixture now ignores only that declared timestamp, while continuing to reject changes to owner bytes and other paths. This also prevents the fixture's own assertion from interrupting the hard-link cleanup recovery test.

Keep fast smoke focused: the platform check runs its one Windows path selftest case instead of all 355, and the generic smoke check no longer repeats the full selftest. test:core and npm test still run the complete selftest explicitly.

Read the current generated handoff section in lazy detect when older authored content is preserved after it. A retained init placeholder no longer makes a successful session close and verification look incomplete; malformed generated markers still block.