Parse Qoder credit usage and show counts as secondary

[SDSLeon]

Type: Feature

• Parse Qoder production credit payloads (snake_case and newer quota shapes) so usage windows report used/limit/percent correctly.
• Enrich snapshots with profile email and plan tier from supplementary APIs when the usages payload omits them, without failing core collection.
• Show credit windows with percent as the primary label and used/limit counts as the muted secondary (same pattern as spend windows).
• Expose the provider usage store on the renderer dev bridge for local inspection.