Answer what the mesh's checks said of a pull request, as mesh-delivery's checks verb (hq ADR 0239)

Reading a pull request's mesh/merge-gate and mesh/repo-check meant scraping the controller's journal:
the forge clips each status to 140 characters and nothing returned the verdict whole. mesh-delivery
already keeps the verdict; it now keeps the machine that ran it, the layers' modules and the report,
and its checks verb joins that to the forge's statuses, read through a new gitea_commit_statuses tool
that also says whether the base's protection lets the commit merge.

after: novox/mesh-controller

modules/gitea/tools/index.ts

@@ -12,6 +12,7 @@ import { registerModuleTools, type ToolDefinition } from "@novox/mesh-sdk/tools"
 import { emit } from "@novox/mesh-sdk/events";
 import { GiteaClient, type BranchProtection } from "../client.js";
 import { appendNote, deliveryStatus, run, viewBody, viewComment } from "../delivery.js";
+import { mergeableUnder, newestByContext } from "../checks.js";
 
 /** The forge's container, where its repositories and git are: the note is written there (novox/hq ADR 0239). */
 const forgeContainer = process.env.MESH_GITEA_CONTAINER || "gitea";
@@ -450,6 +451,47 @@ export function getGiteaTools(gitea: GiteaClient): ToolDefinition[] {
         return { created: await gitea.addComment(owner, repo, number, body) };
       },
     },
+    {
+      name: "gitea_commit_statuses",
+      description: "Read a commit's statuses — or a pull request's head's — as the forge keeps them: the newest of each context (mesh/merge-gate, mesh/repo-check, mesh/delivery, …) with its state, description, link, when it was set and by whom; and whether the branch it merges into would let it merge, every status that branch's protection requires being a success. Reads only.",
+      input: {
+        owner: { type: "string", description: "the repository owner" },
+        repo: { type: "string", description: "the repository name" },
+        number: { type: "number", description: "a pull request's number: its head is read, and its base's protection" },
+        sha: { type: "string", description: "a commit, or the start of one, instead of a pull request" },
+        base: { type: "string", description: "with sha: the branch whose protection is read (default main)" },
+      },
+      run: async (args) => {
+        const owner = String(args.owner ?? "").trim(), repo = String(args.repo ?? "").trim();
+        const number = args.number === undefined || args.number === "" ? 0 : Number(args.number);
+        let ref = String(args.sha ?? "").trim();
+        let base = String(args.base ?? "").trim();
+        if (!owner || !repo) throw new Error("name the repository: owner and repo");
+        if (!Number.isInteger(number) || number < 0) throw new Error(`${args.number} is not a pull request's number`);
+        let pull: { number: number; title: string; state: string; merged: boolean; base?: string; head?: string;
+          head_sha?: string; merge_commit_sha?: string; html_url: string } | undefined;
+        if (number > 0) {
+          const p = await gitea.getPullRequest(owner, repo, number);
+          pull = { number: p.number, title: p.title, state: p.state, merged: p.merged, base: p.base, head: p.head,
+            head_sha: p.head_sha, merge_commit_sha: p.merge_commit_sha, html_url: p.html_url };
+          if (!ref) ref = p.head_sha ?? "";
+          if (!base) base = p.base ?? "";
+          if (!ref) throw new Error(`${owner}/${repo}#${number} names no head commit`);
+        }
+        if (!ref) throw new Error("name a pull request's number or a commit");
+        const combined = await gitea.combinedStatus(owner, repo, ref);
+        const statuses = newestByContext(combined.statuses);
+        base = base || "main";
+        let rule: BranchProtection | null = null, unreadable: string | undefined;
+        try {
+          rule = await gitea.branchProtection(owner, repo, base);
+        } catch (err) {
+          unreadable = err instanceof Error ? err.message : String(err);
+        }
+        return { commit: combined.sha || ref, pull, combined: combined.state, statuses,
+          merge: mergeableUnder(base, rule, statuses, unreadable) };
+      },
+    },
     {
       name: "gitea_commit_status",
       description: "Set one of the mesh's statuses on a commit (mesh/delivery, mesh/delivery-group): pending, success, error, failure or warning, a short description, and the page it links to.",