feat: add plug-and-play devRant API client examples with Python and JavaScript

Add complete set of example scripts for the devRant REST protocol under
examples/devrant/, including reusable client libraries, a rant poster,
a live feed watcher with keyword-based auto-upvote, and an end-to-end
smoke test that exercises every endpoint. Both Python (stdlib-only) and
JavaScript (Node 18+ global fetch) implementations are provided.

examples/devrant/post_rant.mjs

@@ -0,0 +1,20 @@
+// retoor <retoor@molodetz.nl>
+
+import { fromEnv } from "./client.mjs";
+
+const text = process.argv[2];
+const tags = process.argv[3] || "";
+
+if (!text) {
+  console.log("usage: DEVRANT_USERNAME=.. DEVRANT_PASSWORD=.. node post_rant.mjs <text> [tags]");
+  process.exit(1);
+}
+
+const api = fromEnv();
+await api.login();
+const result = await api.postRant(text, tags);
+if (result.success) {
+  console.log(`posted rant ${result.rant_id}`);
+} else {
+  console.log(`failed: ${result.error}`);
+}