Add TaskMarket delegation plugin example

[kimutaiRop]

Summary

• adds a self-contained TaskMarket delegation plugin example for Franklin
• supports read-only discovery of public TaskMarket tasks
• prepares task creation and submission review commands while requiring explicit user authorization before any money-moving CLI action
• documents local install, config, flow, and safety rules

Verification

• npm run build
• node --test --test-reporter=spec test/taskmarket-plugin.local.mjs

TaskMarket fit

This gives Franklin users a concrete extension point for deciding when work should be delegated to external TaskMarket workers instead of spending more inference, while preserving wallet control and spending limits.