Rate limiter too aggressive for batch queue operations

[mriechers]

Issue

The RATE_EXPENSIVE rate limit on POST /api/queue/ blocks legitimate batch operations after ~10 requests per minute. For an internal editorial tool with a single user, this is overly restrictive.

Reproduction

Queue more than 10 jobs in rapid succession — subsequent requests return 429 Too Many Requests.

Suggested Fix

Options (not mutually exclusive):

• Increase the RATE_EXPENSIVE threshold for the queue endpoint
• Add a bulk queue endpoint (POST /api/queue/bulk) that accepts an array of jobs in a single request
• Make rate limits configurable via environment variable
• Exempt authenticated internal requests from rate limiting

Context

The upload endpoint (POST /api/upload/transcripts) already supports batch uploads of up to 20 files. The queue endpoint should have parity.