fix(codeburn): restore menubar token reporting

[zorgy13]

Summary

• restore CodeBurn menubar token reporting evidence and payload compatibility
• verify real Codex token/cost data through menubar JSON and smoke report
• document verification in docs/verification/codeburn-restore-verification.md

Verification

• npm test -- tests/menubar-json.test.ts tests/providers/codex.test.ts tests/usage-aggregator.test.ts tests/minimax.test.ts
• npm run build
• cd mac && swift build
• npx vitest tests/cli-model-savings.test.ts tests/cli-plan.test.ts --testTimeout 30000 --fileParallelism=false
• git diff --check

Notes

• direct push to getagentseal/codeburn.git was denied for zorgy13, so this PR uses a fork branch
• no npm publish, release tag, installed app replacement, or server deploy was run