fix: isolate and safely reap Chrome automation

[ruby-dlee]

Intent

Publish the already-reviewed four-part Chrome automation safety fix while preserving the explicit reversion of all unrelated main-branch Behavior and Herdr CI fixes; leave PR 46 open and do not merge.

What Changed

• Isolate each crew task’s Chrome automation in a dedicated browser profile and process group, with credential-safe launch flags and stable Chrome excluded from automation.
• Reap task-owned browser processes during teardown, failed spawn rollback, and locked bootstrap orphan sweeps, while preserving unrelated and legacy browser processes by default.
• Add lifecycle, routing, cleanup, and macOS smoke coverage plus browser isolation and verification documentation.

Testing

• ⏭️ Test - skipped

Pipeline

Updates from git push no-mistakes

✅ **intent** - passed

✅ No issues found.

✅ **Rebase** - passed

✅ No issues found.

⏭️ **Review** - skipped

Step was skipped.

⏭️ **Test** - skipped

Step was skipped.

⏭️ **Document** - skipped

Step was skipped.

⏭️ **Lint** - skipped

Step was skipped.

✅ **Push** - passed

✅ No issues found.