docs(FN-3468): fix plugin authoring section numbering

- Add missing top-level dashboard views section to the PLUGIN_AUTHORING table of contents
- Renumber downstream section headings and TOC entries to keep numbering sequential
- Add a node:test suite that validates heading order and TOC anchor alignment

Fusion-Task-Id: FN-3468

scripts/__tests__/plugin-authoring-docs.test.mjs

@@ -0,0 +1,87 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const docPath = path.resolve(__dirname, "../../docs/PLUGIN_AUTHORING.md");
+const doc = readFileSync(docPath, "utf8");
+
+const expectedSections = [
+  "Getting Started",
+  "Plugin Manifest Reference",
+  "Plugin Settings Schema",
+  "Available Hooks and Signatures",
+  "Registering Tools",
+  "Registering Routes",
+  "Registering UI Slots",
+  "Registering Top-Level Dashboard Views",
+  "Registering Agent Runtimes",
+  "Plugin Context API Reference",
+  "Plugin Lifecycle States",
+  "Testing Plugins",
+  "Publishing Plugins",
+  "Example Plugins",
+  "Registering Skills",
+  "Registering Workflow Steps",
+  "Plugin Prompt Contributions",
+  "Plugin Binary Setup Hooks",
+];
+
+function slugifyHeading(text) {
+  return text
+    .trim()
+    .toLowerCase()
+    .replace(/[^a-z0-9\s-]/g, "")
+    .replace(/\s+/g, "-");
+}
+
+test("PLUGIN_AUTHORING headings are sequentially numbered 1..18 with expected titles", () => {
+  const headingMatches = [...doc.matchAll(/^##\s+(\d+)\.\s+(.+)$/gm)];
+  const numbered = headingMatches.map((m) => ({ number: Number(m[1]), title: m[2].trim() }));
+
+  assert.equal(numbered.length, expectedSections.length);
+
+  for (let i = 0; i < expectedSections.length; i += 1) {
+    assert.equal(numbered[i].number, i + 1);
+    assert.equal(numbered[i].title, expectedSections[i]);
+  }
+});
+
+test("PLUGIN_AUTHORING TOC includes top-level dashboard views and anchors align to headings", () => {
+  const tocMatch = doc.match(/## Table of Contents\n\n([\s\S]*?)\n---/);
+  assert.ok(tocMatch, "Table of Contents block should exist");
+
+  const tocLines = tocMatch[1]
+    .split("\n")
+    .map((line) => line.trim())
+    .filter(Boolean);
+
+  const tocEntries = tocLines.map((line) => {
+    const m = line.match(/^(\d+)\.\s+\[(.+)\]\(#(.+)\)$/);
+    assert.ok(m, `Invalid TOC line: ${line}`);
+    return {
+      number: Number(m[1]),
+      title: m[2],
+      anchor: m[3],
+    };
+  });
+
+  assert.equal(tocEntries.length, expectedSections.length);
+
+  for (let i = 0; i < expectedSections.length; i += 1) {
+    const sectionNumber = i + 1;
+    const expectedTitle = expectedSections[i];
+    const expectedAnchor = slugifyHeading(`${sectionNumber}. ${expectedTitle}`);
+
+    assert.equal(tocEntries[i].number, sectionNumber);
+    assert.equal(tocEntries[i].title, expectedTitle);
+    assert.equal(tocEntries[i].anchor, expectedAnchor);
+  }
+
+  const topLevelEntry = tocEntries.find((entry) => entry.number === 8);
+  assert.ok(topLevelEntry, "TOC should include section 8");
+  assert.equal(topLevelEntry.title, "Registering Top-Level Dashboard Views");
+});