docs(#3037): record OMP first-class runtime support as out-of-scope (#3048)

The request has now been raised three times (#874, #1948, #3037) because the
original denial was recorded only in a closed issue and was therefore invisible
to the prior-denial check. This entry makes the decision discoverable.

Co-authored-by: sim <sim@local>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

.out-of-scope/omp-runtime-in-core.md

@@ -0,0 +1,69 @@
+# OMP (Oh My Pi) as a first-class runtime in gsd-core
+
+gsd-core does not add `omp` (Oh My Pi) as a first-class runtime: no
+`capabilities/omp/capability.json`, no `omp` entry in the runtime registry, no
+`omp` alias canonicalization, and no installer runtime selection for it.
+
+This is a **scope** decision, not a judgement about OMP or about the quality of
+the proposals that have asked for it.
+
+## Why this is out of scope
+
+- **GSD is not expanding its supported-runtime set.** The long-term direction is
+  to *reduce* the number of supported runtimes, not grow it, absent funded
+  development. Each first-class runtime is a permanent maintenance obligation
+  across the registry, installer, artifact conversion, agent discovery, model
+  routing, dispatch isolation, golden install-parity fixtures, and localized
+  capability matrices — carried indefinitely by the project, for a host it does
+  not control.
+- **Host integration is the supported direction, and it is already available.**
+  The Embeddable Orchestration System (ADR-1239) exists precisely so a host can
+  embed GSD and declare its own capabilities, instead of GSD resolving the host
+  from an in-tree registry. An out-of-tree host plugin needs no runtime
+  descriptor. `GSD_AGENTS_DIR` is a documented Priority-1 override honored for
+  *any* runtime name (`src/agent-install-check.cts`, `getAgentsDir`), so a plugin
+  can own its filesystem layout without core knowing the runtime exists.
+- **The ask as filed also carried a defect.** #3037 proposed canonicalizing
+  `pi`, `oh-my-pi` and `pi-coding-agent` to `omp`. OMP is a *fork* of pi
+  (pi.dev), and gsd-core already ships a distinct `pi` runtime
+  ([`capabilities/pi/capability.json`](../capabilities/pi/capability.json), home
+  `~/.pi/agent`, tier 2). That alias list would relocate an existing shipped
+  runtime's config home rather than add a new one. This is recorded so a future
+  revision does not repeat it — it is a correction, not an additional ground for
+  the decision.
+
+## What this does NOT cover
+
+This entry denies **in-tree, first-class runtime registration for OMP**. It does
+not deny, and should never be cited against:
+
+- **Shipping an out-of-tree host plugin for OMP, or for any other host.** This
+  is welcome and supported. `gsd-omp` is already listed in
+  [`docs/registries/eos.json`](../docs/registries/eos.json) and remains listed;
+  registry inclusion is explicitly non-endorsement and is unaffected by this
+  decision.
+- **Feature capabilities** (`role: "feature"`) published out-of-tree under
+  ADR-1244. That is a different axis — *what loop behavior you add*, not *which
+  runtime you are*.
+- **Fixing defects that happen to surface through a non-registered runtime**, or
+  improving the documented override contracts a host plugin depends on.
+- **Any other runtime's support tier.** This entry is about OMP specifically and
+  says nothing about existing runtimes, including `pi`.
+
+**Revisit if** third-party `role: "runtime"` descriptors become loadable from
+outside the repo — ADR-857 D8 defers this to a purely additive external loader
+that has not been delivered — or if funded development changes the maintenance
+calculus that makes an additional first-class runtime unaffordable.
+
+## Prior requests
+
+- #874 — "feat: Native OMP (Oh My Pi) Runtime Support" (closed not planned,
+  2026-06-08)
+- #1948 — "Add Oh My Pi / OMP as a supported runtime" (closed as duplicate of
+  #874)
+- #1947 — implementation PR for #874 (closed unmerged)
+- #3037 — "feat: complete first-class OMP runtime descriptor and registry
+  integration" (closed not planned; the decision this entry records)
+
+*The first denial was never written down here, so the same request returned
+twice more. That is the reason this file exists.*