machine-bridge-mcp v3.0.0-beta.16

Pending-call recovery and verified handover

• Separate the upstream MCP host/connector shard-mapper incident from Machine Bridge evidence. The exact temporary-keyspace error never appeared in Worker or daemon diagnostics and did not increment Worker server-error counters, so it is documented as an external boundary failure with unknown platform ownership rather than misclassified as a local daemon, OAuth, Git, or Cloudflare defect.
• Close the Machine Bridge failure-amplification path discovered after recovery. Pending calls now retain monotonic operation and reconnect deadlines, schedule the earliest deadline through the Durable Object alarm, and run a compensating overdue sweep on every HTTP/WebSocket event. In-memory timers remain the fast path; a transient alarm-storage error is observable without converting already-dispatched work into a false terminal failure.
• Make verified same-instance daemon handover atomic with respect to in-flight calls. Both attached and detached records move to the replacement before the incumbent closes, the complete resume_calls set is sent, remaining operation timeout is preserved, and failed replacement acknowledgement restores ownership to a still-open incumbent.
• Add deterministic disabled-timer deadline tests, direct runtime-alarm scheduling/failure tests, and a real Wrangler/workerd race regression that connects a same-instance replacement while the incumbent still owns an active call. The call remains active rather than detached and completes through the verified replacement.
• Use null-prototype dictionaries for managed-job env and env_resources, so valid variable names such as __proto__, constructor, toString, and valueOf remain ordinary own data instead of mutating JavaScript object prototypes. Add behavior coverage without weakening duplicate-variable rejection.
• Correct architecture and operations documentation that still described Durable Object waitUntil ownership or direct rejection during socket replacement. Document the three deadline enforcement paths, stale-pending diagnosis, host/connector internal-storage error triage, and the exact test evidence.