fix: add backward-compatible gt/bd command fallbacks

[web3dev1337]

Summary

• add backward-compatible polecat lifecycle command fallbacks in server.js
  • prefer modern gt session start/restart <rig>/<polecat>
  • fallback to gt polecat wake <rig>/<polecat> where available
  • fallback to legacy gt sling --rig <rig> --agent <name>
• add backward-compatible rig bootstrap agent-bead creation fallback
  • first try legacy bd create --agent-rig --role-type
  • on unknown-flag errors, retry with modern-compatible bd create --type agent + description/labels
• add real-server integration coverage for both fallback paths and update codebase docs

Why

Upstream gt/bd command surfaces changed between older and newer releases.
Without fallback behavior, GUI operations can fail depending on installed CLI version.
This patch keeps behavior working across both old and current command variants.

Validation

• npm test -- test/integration/cli-compatibility.test.js
• npm test
• npm run test:e2e
• npm run build (expected fail: no build script in this repo)

Notes

• Existing bd --no-daemon compatibility fix remains in separate PR: fix: make bd gateway compatible across old/new beads versions #23