feat: scaffold CLI and minimal issue list (task 0001)

Tracer bullet for gitea-axi: runnable npm package on axi-sdk-js with
gitea-js as the sole HTTP layer, ESM on Node 20+.

- issue list with --state/--limit, default fields, count line from
  X-Total-Count, type=issues guard, explicit empty state, and next-step
  suggestions
- repo context detection from the git origin remote (SSH/scp/HTTPS),
  tea credential discovery with the three-way login-matching split, and
  -R/--repo and --login overrides (flag > env > auto)
- token retrieval via tea login helper get: tea's login list JSON
  carries no token (ADR 0001 amended)
- full AxiError classification table with path-based 404 split, TOON
  errors on stdout, exit codes 0/1/2
- test mode (GITEA_AXI_API_URL/TOKEN/REPO) suppressing subprocesses,
  fixture server, and vitest suites driving the CLI seam (50 tests)

src/client.ts

@@ -0,0 +1,10 @@
+import { giteaApi, type Api } from "gitea-js";
+import type { RepoContext } from "./context.js";
+
+export type GiteaClient = Api<unknown>;
+
+export function createClient(context: RepoContext): GiteaClient {
+  return giteaApi(context.apiUrl, {
+    token: context.token || undefined,
+  });
+}