Per-service throughput mismatches

[codihuston]

Cause: Independent pool sizing can create bottlenecks (e.g., scene detection vs transcription).
Analysis: Throughput imbalance causes backlogs and inefficient resource use.
Acceptance Criteria:

• Documented throughput assumptions and balanced pool sizes.
• Ability to tune pools per environment.
  Solution Approach:
• Add capacity planning defaults and per-service configs.