Update maintainer_guide.md to v2 — workflow, philosophy, and translation banners

[Syknapse]

What needs updating

`maintainer_guide.md` describes the old v1 manual workflow (reviewing PRs by hand, resolving merge conflicts, using GitKraken). The project is now on v2 — card submissions are fully automated. The guide is misleading to any new maintainer.

The file also ends with dangling stub text that was never removed (`Paste this into the file`, `Commit message:`, `PR description:` with no content).

What the update should include

Remove the v1 workflow sections:

• Manual PR review checklist (the bot handles this)
• Merge conflict resolution for cards (archiving eliminates this)
• GitKraken / local tooling recommendation for card merges
• The trailing stub text

Add v2 workflow section:

• Overview of the automated pipeline (validate → automerge → archive)
• What a maintainer actually does now: approve ci.yml workflows for flagged contributors, handle `Remove Card` requests via GitHub Actions, monitor the Actions tab for failed archive runs and re-trigger manually if needed
• Link to `archive/README.md` for archive operations

Add project philosophy section (matching the principles in `CLAUDE.md`):

• Contributors first
• Minimum maintainability
• Simplicity — no over-engineering

Translation files

All translation files in `translations/maintainer_guide/` describe the v1 workflow and are now outdated. Two tasks:

1. Add an outdated banner to the top of every translation file (same pattern as README translations):

```markdown

⚠️ This translation is outdated.
It describes the old v1 manual workflow. The project now uses automated validation and merging (v2).
Please refer to the English maintainer guide for current instructions.
```

2. Update the language table in `maintainer_guide.md` to note that translations are currently outdated.

This is a good first contribution for a maintainer who wants to help — translating the updated guide into their language once the English version is updated.

Notes

Do not attempt to re-translate the full guide — translations are community-maintained. The English guide update + outdated banners on translations is the scope.