gitea: post a pull request's change plan with its verdict (hq ADR 0238)

The gate's status says what the change does and how it was judged; a change that builds
something gets its plan as a comment — the tiers, what each machine receives, and what
is not an ordinary send.

modules/gitea/test/pulls.test.ts

@@ -83,3 +83,21 @@ test("a commit status is set on the commit, under the merge check's context", as
   assert.equal(seen!.body.state, "failure");
   assert.equal(seen!.body.context, "mesh/merge-gate");
 });
+
+test("a change plan is the gate's result: said on the status and, when it builds something, as a comment", async () => {
+  const { statusFor, commentFor } = await import("../pulls.ts");
+  const plan = {
+    repository: "novox/mesh-catalog", base: "main", head: "0123456789abcdef", moved: ["gitea"],
+    tiers: [["gitea"]], machines: [{ machine: "anchor", receives: ["gitea"] }], steps: [],
+    summary: "builds gitea → anchor; no bus step",
+  };
+  const c = { owner: "novox", repo: "mesh-catalog", number: 7, commit: "0123456789abcdef", id: "b", verdict: "pass",
+    summary: "every machine composes", gate: { verdict: "pass", summary: "every machine composes", modules: ["gitea"] }, plan };
+  assert.equal(statusFor(c).description, "pass: builds gitea → anchor; no bus step; every machine composes");
+  const said = commentFor(c) ?? "";
+  assert.match(said, /Change plan\*\* — builds gitea → anchor/);
+  assert.match(said, /- anchor: receives gitea/);
+  // A plan that builds nothing, passing: the statuses say it, no comment.
+  const nothing = { ...c, plan: { ...plan, moved: [], tiers: [], machines: [], summary: "builds nothing" } };
+  assert.equal(commentFor(nothing), null);
+});