Improve Strategy 27 event readability

[jackhai9]

Summary

• replace dense TradingView text annotations with one marker per Strategy 27 event
• add a compact fixed event panel with four-force details and recent-event navigation
• format user-visible values with stable precision and compact notional units
• guard against orphan markers when the chart layer resets during asynchronous rendering

Validation

• npm run test:binance-strategy27-events (31 passed)
• npm test (579 passed)
• build, syntax check, artifact inspection, and git diff check passed
• independent read-only review passed with no remaining findings
• Tampermonkey installed source matches the generated 0.2.0 artifact exactly