feat: performace lables for gitea

docs/README.md

@@ -1,3 +1,23 @@
 # Documentation
 
 - [Using the `hectic` Attic Cache](./attic-cache.md)
+
+## Gitea runner labels
+
+Common labels for zero-idle runners:
+
+- `ubuntu-latest` — default Ubuntu-style smoke / host runner path
+- `nix` — Nix-capable runner path
+- `gross-x86` — x86 fallback chain `cx53` / `cx43` / `cx33`
+- `gross-arm` — ARM fallback chain `cax41` / `cax31` / `cax21`
+- `gross-x86-perf` — x86 performance chain `cx53` / `cpx62` / `cpx52`
+- `gross-mixed-econ` — mixed chain `cx53` / `cax41` / `cx43`
+- `gross-nix-x86` — `gross-x86` + Nix bootstrap
+- `gross-nix-arm` — `gross-arm` + Nix bootstrap
+- `gross-nix-x86-perf` — `gross-x86-perf` + Nix bootstrap
+- `gross-nix-mixed-econ` — `gross-mixed-econ` + Nix bootstrap
+
+Region order for fallback: `nbg1`, then `fsn1`, then `hel1`.
+
+Operational details: `infra/gitea-runners/runbook.md` and
+`package/gitea-runner-controller/decide.sh`.