feat(reusable): add the 4090 Ti (qwen3.6-27b via llama-swap) to the default swarm

Adds a local GPU reviewer to the shared default:
- models += ragnaros/qwen3.6-27b
- GADFLY_ENDPOINT_RAGNAROS=llama-swaps|https://llama-swap.ragnaros.dudenhoeffer.casa
  (plain LAN URL, no credential; registers provider "ragnaros")
- provider_concurrency ragnaros=1, provider_lens_concurrency ragnaros=1
  (one model, one lens at a time — a single local GPU)

Inherited by all @v1 consumers (mort/executus/majordomo) once v1 moves.
Comments + README + CLAUDE.md updated.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -40,7 +40,7 @@ it. Drop one file in your repo and set a couple of secrets/vars:
    your repo. Two flavors: the slim [`reusable.yml`](examples/reusable.yml) — a tiny caller of
    Gadfly's **reusable workflow** (`uses: steve/gadfly/.gitea/workflows/review-reusable.yml@…`,
    forwarding only the secrets the reviewer needs), which ships a **default swarm** (3 cloud models +
-   the Claude Code engine, 5-lens suite) you inherit by omitting `with:` or override per-input — or the full self-contained
+   the Claude Code engine + a local 4090 Ti via llama-swap, 5-lens suite) you inherit by omitting `with:` or override per-input — or the full self-contained
    [`adversarial-review.yml`](examples/adversarial-review.yml) (Ollama Cloud default, with inline
    notes for every provider / local Ollama / OpenAI-compatible / endpoint aliases). See the
    [examples index](examples/README.md).