First slice of the RunPod remote-GPU backend (rent cloud GPUs, proxy inference).
Dormant unless enabled — no request path yet.

- config.py: RunpodConfig (enabled/api_key/cloud_type/api_base/rest_base/
  serverless_base/default_gpu_type/data_center/global_max_hourly_usd); registered,
  loaded, serialized. get_active_runpod_config() in manager.py.
- codai/api/runpod_client.py: GraphQL client — ping, list_gpu_types (+prices),
  pick_gpu (cheapest under a $/hr ceiling, VRAM filter, spot-aware), create_pod
  (on-demand + interruptible/spot), get_pod, stop/terminate, list_pods, wait_ready.
  API key via ?api_key=, masked in all error strings.
- admin: settings GET/save runpod block (key masked, overwritten only on a real
  new value); GET /admin/api/runpod/gpu-types (key check + catalog) and
  /admin/api/runpod/status (pods + live $/hr).
- settings.html: RunPod card (key/cloud/default-gpu/global $/hr cap/DC/advanced
  bases) + "Test key & list GPUs" button.

Decisions locked: host in primary engine (Layer-2, zero local VRAM); default
vLLM-OpenAI pod image; per-model $/hr + global budget; per-model allow_spot;
mode pods|serverless per model. TODO (request-path phase): RunPod requests must
bypass the GLOBAL concurrency gate only (QueueManager.max_parallel_requests).

Client GraphQL field names written from docs — pending live verification with a key.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01R6iugoNeEgt9PkajKrFyq4