Read branch protection as the forge's administrator, so builds register again

The forge answers a repository's protection rules to its administrator
alone, and the tools' account no longer is one (ADR 0365), so every
delivery building a module failed at the controller's build-source check
with a 403. gitea_branch_protection_get now reads the rules with the
administrator account (ADR 0375); it only reads, and the protection set
and every write stay refused to the tools' account. Issue 772.

Co-Authored-By: Claude <noreply@anthropic.com>

modules/gitea/test/protection-read.test.ts

@@ -0,0 +1,59 @@
+// The controller's build-source check asks gitea_branch_protection_get for a repository's rules, which the forge
+// answers to a repository's administrator alone. The tools' account is not one (novox/hq ADR 0365 §2), so the read
+// goes with the forge's administrator account, and only the read (ADR 0375, issue 772): a protection edit through the
+// tools still gets the forge's refusal.
+
+import { test, after } from "node:test";
+import assert from "node:assert/strict";
+import { createServer } from "node:http";
+
+import { GiteaAdmin, GiteaClient } from "../dist/client.js";
+import { ConfiguredToken } from "../dist/token.js";
+import { getGiteaTools } from "../dist/tools/index.js";
+
+const adminBasic = "Basic " + Buffer.from("mesh-admin:secret").toString("base64");
+const rules = [
+  { rule_name: "main", enable_push: false, enable_status_check: true, status_check_contexts: ["mesh/merge-gate"], block_admin_merge_override: true },
+  { branch_name: "release", enable_push: false },
+];
+const seen: string[] = [];
+
+const server = createServer((req, res) => {
+  const path = (req.url ?? "").replace(/^\/api\/v1/, "");
+  const as = req.headers.authorization === adminBasic ? "admin" : "tools";
+  seen.push(`${req.method} ${path} as ${as}`);
+  const send = (status: number, body: unknown) => { res.writeHead(status, { "Content-Type": "application/json" }); res.end(JSON.stringify(body)); };
+  if (path.includes("/branch_protections")) {
+    if (as !== "admin") return send(403, { message: "user should be an owner or a collaborator with admin write of a repository" });
+    if (req.method === "GET") return send(200, rules);
+  }
+  send(404, { message: "not found" });
+});
+await new Promise<void>((r) => server.listen(0, "127.0.0.1", () => r()));
+after(() => new Promise<void>((r) => server.close(() => r())));
+const { port } = server.address() as { port: number };
+const url = `http://127.0.0.1:${port}`;
+const tools = getGiteaTools(new GiteaClient(url, new ConfiguredToken("tools-token")), () => new GiteaAdmin(url, "mesh-admin", "secret"));
+const tool = (name: string) => tools.find((t) => t.name === name)!;
+
+test("gitea_branch_protection_get answers every rule, read with the administrator account the tools' token cannot read with", async () => {
+  const out: any = await tool("gitea_branch_protection_get").run({ owner: "novox", repo: "mesh-controller" });
+  assert.deepEqual(out.rules.map((r: any) => r.rule), ["main", "release"]);
+});
+
+test("gitea_branch_protection_get answers the rule for a branch, null when it has none", async () => {
+  const main: any = await tool("gitea_branch_protection_get").run({ owner: "novox", repo: "mesh-controller", branch: "main" });
+  assert.equal(main.branch, "main");
+  assert.equal(main.rule.rule, "main");
+  assert.equal(main.rule.admin_may_override, false);
+  const none: any = await tool("gitea_branch_protection_get").run({ owner: "novox", repo: "mesh-controller", branch: "dev" });
+  assert.equal(none.rule, null);
+});
+
+test("gitea_branch_protection_set still gets the forge's refusal, as the tools' account", async () => {
+  await assert.rejects(
+    tool("gitea_branch_protection_set").run({ owner: "novox", repo: "mesh-controller", branch: "main", status_checks: "mesh/merge-gate" }),
+    /403/,
+  );
+  assert.ok(!seen.some((s) => /^(PATCH|POST|PUT|DELETE) .*branch_protections.* as admin$/.test(s)), seen.join("\n"));
+});