feat: add experimental resilient LAN Worker v1 protocol

[tobybgy-lsd]

Summary

• add opt-in LAN Worker registration, pairing, heartbeat, capability inventory, revocation, persistent tasks, renewable leases, fencing tokens, checkpoints, ordered logs, and SHA-256 evidence upload
• add a configuration-driven Adapter SDK for existing RPA masters with doctor, start, stop, health, progress, logs, checkpoints, evidence directories, and strict success checks
• add worker doctor --config ... --offline for local readiness checks without exposing worker secrets
• publish a generic Android scrcpy visual sidecar with mirror-check, mirror-start, and evidence-safe record-screen CLI commands
• reject immediate scrcpy process exit instead of reporting a false start; recording requires a non-empty output before success
• document which local capabilities are public-safe and which business configs, account state, evidence, duplicate job trees, and bypass material remain local

Validation

• full stdlib suite: 637 tests passed, 4 skipped
• focused Android mirror coverage: 7 tests passed
• local scrcpy 4.0 dependency check passed
• wheel and sdist build and Twine checks passed
• freshly built package private-content scan: 0 findings
• local safety scan passed
• clean wheel install, Android mirror import, and CLI smoke passed
• no ADB device was online for this update, so no new real-device recording is claimed

Remaining acceptance gates

• Run a real two-computer LAN smoke with the production master-script adapter
• Verify disconnect, lease expiry, checkpoint resume, graceful stop, logs, and evidence transfer across the real network
• Run a short real-device record-screen smoke when an authorized ADB device is online

Kept as Draft until the two-computer smoke is available; local and CI tests are not presented as production LAN acceptance.

[tobybgy-lsd]

Release status: experimental and opt-in. Local/CI contracts are verified, but two-computer production acceptance remains intentionally open; this merge does not claim LAN production readiness.