fix: dedupe auth rotation by email

[MasakiMu319]

• Summary
  • Treat multiple auth files with the same account email as a single account by deduplicating rotation/switching to the latest auth
    index.
  • Add a manual cleanup action to delete duplicate auth files (keep highest index per email), with English logs and UI i18n support.
• Key Changes
  • Deduplicate account rotation indices by normalized email (accountName), keeping the highest auth-N index per email.
  • Redirect manual “switch to specific index” requests to the canonical (latest) index when the target is a duplicate.
  • Startup and “switch next” logic now use deduped rotation indices.
  • Add POST /api/accounts/deduplicate (session-authenticated) to remove duplicate auth files; logs are in English and include the
    index-ordering assumption.
  • Enhance /api/status payload with rotationIndicesRaw and duplicateIndicesRaw; UI displays deduped/duplicate counts, marks duplicates,
    and adds a “Deduplicate Auth” button with i18n strings (EN/ZH).
• How to Test
  • Create configs/auth/auth-0.json and auth-1.json with the same accountName email.
  • Check Status page: “Available Accounts (Deduped)” only includes [1], and “Duplicate Auth” includes [0].
  • Try switching to #0 auth json: it should redirect to #1 auth json (latest).
  • Click “Deduplicate Auth”: auth-0.json is deleted, logs show keep/delete in English, and status updates accordingly.
• Notes / Assumptions
  • “Latest” is determined by the highest auth index, assuming indices are created in chronological order for the same account.

[bbbugg]

Thanks for the PR! The core logic for email-based deduplication is solid, and the code quality is great 👍

After testing and reviewing the code, I think there are a few areas we can refine further. I'll make these changes after merging this PR:

1. Manual Account Switching Should Not Auto-Redirect

When a user manually selects a specific account to switch to, we should respect their choice rather than auto-redirecting to the latest index of the same email. Reasons:

• The user is making a deliberate choice
• The UI already shows a duplicate indicator (e.g., "duplicate of #X")
• Auto-redirecting may confuse users (selected #0, but ended up on #5)

2. New Auth Index Strategy

I'm also planning to change the new auth index allocation to always be greater than the current maximum index, instead of searching for gaps starting from 0. This simplifies the assumption that higher index = newer auth.

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Thanks again for the contribution! 🙏

[MasakiMu319]

I’d be happy to see that. 🤗