Discover plugins at boot (todo §2); scan plugins/, import + validate each plugin.ts default export, fail loud on bad plugin/conflict

src/server.ts

@@ -1,8 +1,12 @@
 import { createApp } from "./app.ts";
 import { loadConfig } from "./config.ts";
+import { discoverPlugins } from "./discovery.ts";
 
 const config = loadConfig(); // validates the env (incl. enforced secrets) — fails loud at boot
 
+const plugins = await discoverPlugins(); // scans plugins/, validates — fails loud on a bad plugin (router wiring is next §2)
+console.log(`Discovered ${plugins.length} plugin(s)${plugins.length ? `: ${plugins.map((p) => p.id).join(", ")}` : ""}`);
+
 const server = createApp({ cache: config.cacheTemplates }).listen(config.port, () => {
   console.log(`Listening on http://localhost:${config.port}`);
 });