fix(minimax): fall back to remaining_percent when count fields are zero

[ASF-E-OBJECTTOOBIG]

Summary

MiniMax's international Coding Plan endpoint now returns current_interval_total_count: 0 / current_interval_usage_count: 0for thegeneralandvideorows, with actual usage carried incurrent_interval_remaining_percent/current_weekly_remaining_percent(pluscurrent_*_status` for limit state).

The current parser drops any record with total <= 0, so affected users see no reportable MiniMax Coding Plan quota.

This is the follow-up to #150 — that fix added the general/video model-name match but assumed counts would still be populated. This PR:

1. Adds a getPercentRemaining accessor to each entry in MINIMAX_WINDOW_SPECS reading current_interval_remaining_percent / current_weekly_remaining_percent.
2. Rewrites buildMiniMaxEntry so that when count fields are missing/zero, it falls back to the percent field instead of returning null. The count-based path is preserved unchanged for any response shape that still populates totals.
3. Relaxes isMiniMaxModelRecord to accept a record with current_interval_remaining_percent even when count fields are absent, hardening against further API drift.

The percent path reuses the existing roundPercent helper, matching upstream's "negative percentages allowed" contract.

Linked Issue

Fixes #171

OpenCode Validation

• Current production released OpenCode version tested: 1.17.11
• Why this version is relevant to the fix: this is the version running against the patched plugin locally during validation. Local diff applied against dist/providers/minimax-coding-plan.js (v3.11.2) confirmed /quota_status now reports five_hour_usage: 14% remaining and weekly_usage: 10% remaining for the user's actual MiniMax API payload.

Quality Checklist

• I ran pnpm run typecheck
• I ran pnpm test
• I ran pnpm run build
• This is the smallest safe root-cause fix (no unnecessary hook/output mutation logic)
• I preserved behavioral invariants and updated/added boundary tests as needed
• I updated docs for user-facing workflow/command/config changes (README.md and CONTRIBUTING.md when applicable)
• For new API-key/token providers, I started from contributing/provider-template/ or explained why the template does not apply
• For provider setup/auth wording changes, I checked the relevant dummy .ts template in contributing/provider-template/ and verified README.md against src/lib/provider-metadata.ts (authentication/authFallbacks) and provider auth resolver/diagnostics behavior

[slkiser]

Thanks for the fix and validation. This was integrated into v4.0.1, including the remaining-percentage fallback for zero-count MiniMax responses. Closing this PR as completed.