refactor: remove XPRT tools and Persistence-Interop backend (#16)

* refactor: remove XPRT tools and Persistence-Interop backend

Extracted to standalone xprt-farming-toolkit package:
- Removed xprt-farm.ts, xprt-staking.ts, xprt-rewards.ts
- Removed backends/persistence.ts
- Cleaned up tool registrations in index.ts

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* chore: remove local-only files from branch

Remove docs/npm_publish.md, marketing/screenrecord.md, and other
local files that should not be in the PR.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

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Co-authored-by: Claude Opus 4.6 (1M context) <[email protected]>

Merge pull request #15 from persistenceOne/fix/proxy-sign-and-execute

fix: add signAndExecute to ProxyBackend for Persistence Interop MCP flow

Merge pull request #10 from persistenceOne/pre-launch

fix: LiFi address checksumming & leaderboard-based reward multipliers (v0.3.2)

Merge pull request #8 from persistenceOne/feat/dockerfile

feat: add Dockerfile for Glama safety/quality checks