feat: initial commit - Microsub endpoint for Indiekit

Fork of @indiekit/endpoint-microsub with customizations.
Enables subscribing to feeds and reading content using the Microsub protocol.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

index.js

@@ -0,0 +1,63 @@
+import express from "express";
+
+import { microsubController } from "./lib/controllers/microsub.js";
+import { createIndexes } from "./lib/storage/items.js";
+
+const defaults = {
+  mountPath: "/microsub",
+};
+const router = express.Router();
+
+export default class MicrosubEndpoint {
+  name = "Microsub endpoint";
+
+  /**
+   * @param {object} options - Plugin options
+   * @param {string} [options.mountPath] - Path to mount Microsub endpoint
+   */
+  constructor(options = {}) {
+    this.options = { ...defaults, ...options };
+    this.mountPath = this.options.mountPath;
+  }
+
+  /**
+   * Microsub API routes (authenticated)
+   * @returns {import("express").Router} Express router
+   */
+  get routes() {
+    // Main Microsub endpoint - dispatches based on action parameter
+    router.get("/", microsubController.get);
+    router.post("/", microsubController.post);
+
+    return router;
+  }
+
+  /**
+   * Initialize plugin
+   * @param {object} indiekit - Indiekit instance
+   */
+  init(indiekit) {
+    console.info("[Microsub] Initializing endpoint-microsub plugin");
+
+    // Register MongoDB collections
+    indiekit.addCollection("microsub_channels");
+    indiekit.addCollection("microsub_items");
+
+    console.info("[Microsub] Registered MongoDB collections");
+
+    // Register endpoint
+    indiekit.addEndpoint(this);
+
+    // Set microsub endpoint URL in config
+    if (!indiekit.config.application.microsubEndpoint) {
+      indiekit.config.application.microsubEndpoint = this.mountPath;
+    }
+
+    // Create indexes for optimal performance (runs in background)
+    if (indiekit.database) {
+      createIndexes(indiekit).catch((error) => {
+        console.warn("[Microsub] Index creation failed:", error.message);
+      });
+    }
+  }
+}