docs(commands): document /usage slash command

src/docs/slash-commands-doc.test.ts

@@ -0,0 +1,32 @@
+import fs from "node:fs/promises";
+import path from "node:path";
+import { describe, expect, it } from "vitest";
+
+import { listChatCommands } from "../auto-reply/commands-registry.js";
+
+function extractDocumentedSlashCommands(markdown: string): Set<string> {
+  const documented = new Set<string>();
+  for (const match of markdown.matchAll(/`\/(?!<)([a-z0-9_-]+)/gi)) {
+    documented.add(`/${match[1]}`);
+  }
+  return documented;
+}
+
+describe("slash commands docs", () => {
+  it("documents all built-in chat command aliases", async () => {
+    const docPath = path.join(
+      process.cwd(),
+      "docs",
+      "tools",
+      "slash-commands.md",
+    );
+    const markdown = await fs.readFile(docPath, "utf8");
+    const documented = extractDocumentedSlashCommands(markdown);
+
+    for (const command of listChatCommands()) {
+      for (const alias of command.textAliases) {
+        expect(documented.has(alias)).toBe(true);
+      }
+    }
+  });
+});