test(azure): stabilize R4 behavior shards

[ruby-dlee]

Summary

• make the watcher-lock fixture wait for the replacement process to finish exec before capturing its identity
• make the OpenCode watcher test await the production readiness coordinator instead of a fixed one-second poll
• keep the secondmate address-pinning graph test hermetic under zero origin egress without skipping it

Testing

• full networkless fm-teardown-b suite, 73/73 part-B cases
• watcher suite with a 250 ms pre-exec adversary
• Pi/OpenCode suite at 0.2 CPU with a two-second delayed arm
• behavior shard planner and suite seal
• full pinned shell lint, 252 scripts
• Bash syntax, Python compile, and diff checks

Context

These are the three test-harness failures reproduced from the fresh R4 Azure validation cell. Production identity, timeout, and network authority checks are unchanged.