Bug: quota --output json field current_interval_usage_count shows remaining quota, not usage

[xandersbell]

Bug Description

When running `mmx quota show --output json`, the field `current_interval_usage_count` does not represent what its name implies.

Actual behavior: The value is the number of remaining calls available in the current interval.

Expected behavior: `current_interval_usage_count` should represent calls already used.

Steps to Reproduce

```bash
mmx quota show --output json --quiet
```

Sample output:

```json
{
"model_name": "MiniMax-M*",
"current_interval_total_count": 1500,
"current_interval_usage_count": 1417
}
```

If `usage_count = 1417` with `total_count = 1500`, the remaining should be `1500 - 1417 = 83`. However, the quota actually expires after ~83 more calls — suggesting `1417` represents the remaining quota, not used amount.

Suggested Fix

Rename `current_interval_usage_count` → `current_interval_remaining_count` to match the actual meaning, or add a separate field for actual usage.

[xandersbell]

Fixed in PR #69 — --output json now adds current_interval_remaining_count and current_weekly_remaining_count fields (semantically correct), while preserving original usage_count fields for backward compatibility. --quiet mode also corrected.

[xandersbell]

Updated: PR #69 now fixes the existing current_interval_usage_count / current_weekly_usage_count field values directly (no new fields, no schema change). Values are corrected to actual usage, resolving the semantic mismatch.

[xandersbell]

PR #69 update: initial commit added new fields (current_interval_remaining_count) for the correct semantics. After review, we reverted to fix only the existing field values in-place — no new fields, no schema change — to respect the original API contract.