Add a new scenario: firmware-update-success

[sepehr-safari]

Good First Issue

Add a new scenario firmware-update-success — a successful firmware update with no failures.

What to do

1. Create packages/toolkit/src/scenarios/__scenarios__/firmware-update-success.ts
2. Create a synthetic trace with: BootNotification → FirmwareStatusNotification (Downloaded) → FirmwareStatusNotification (Installed) → Heartbeat
3. Set expectedFailures: []
4. Import and register in packages/toolkit/src/scenarios/index.ts
5. Update scenario count in packages/toolkit/src/scenarios/index.test.ts and tests/external-fixture/test.mjs
6. Run ocpp-debugkit ci to verify all pass

Guidelines

• All data must be synthetic (use CS-SYNTHETIC-NNN for station IDs)
• Follow the pattern in existing scenario files (e.g., diagnostics-failure.ts)
• Add the assertions field with at least one assertion (e.g., no_failures)

Files to modify

• packages/toolkit/src/scenarios/__scenarios__/firmware-update-success.ts (new)
• packages/toolkit/src/scenarios/index.ts (register)
• packages/toolkit/src/scenarios/index.test.ts (update count)
• tests/external-fixture/test.mjs (update count)

How to claim

Comment "I'd like to work on this" and it will be assigned to you.

Please hold one open claim at a time. Once the pull request for it is merged,
say which issue you want next and it will be assigned. That keeps issues from
sitting claimed while another is still in review, so other newcomers can see
what is genuinely free.

[YANGCHUNHONG3000]

I'd like to work on this firmware-update-success scenario.

[YANGCHUNHONG3000]

I'd like to work on this.