Add billing pricing + quota for the 3 models (qbraid-api) #38

Question

In qbraid-api, add MODEL_PRICING entries (and any subscription-tier quota) for the 3 model ids in src/features/billing/ai-chat/ai-chat.types.ts — without them, the gateway's validate / deduct calls fail for these models.

Decide pricing: list price vs qBraid markup policy, using the per-model input/output/cache figures from the discovery ticket. Model ids must match the gateway's codeqModelId.