Make POW configurable, expose over the API

src/app.ts

@@ -1,3 +1,4 @@
+import { Conf } from '@/config.ts';
 import '@/cron.ts';
 import {
   type Context,
@@ -103,7 +104,7 @@ app.post('/oauth/revoke', emptyObjectController);
 app.post('/oauth/authorize', oauthAuthorizeController);
 app.get('/oauth/authorize', oauthController);
 
-app.post('/api/v1/acccounts', requireProof({ pow: 20 }), createAccountController);
+app.post('/api/v1/acccounts', requireProof({ pow: Conf.pow.registrations }), createAccountController);
 app.get('/api/v1/accounts/verify_credentials', requirePubkey, verifyCredentialsController);
 app.patch('/api/v1/accounts/update_credentials', requirePubkey, updateCredentialsController);
 app.get('/api/v1/accounts/search', accountSearchController);

src/config.ts

@@ -126,6 +126,12 @@ const Conf = {
       'system',
     ];
   },
+  /** Proof-of-work configuration. */
+  pow: {
+    get registrations() {
+      return Number(Deno.env.get('DITTO_POW_REGISTRATIONS') ?? 20);
+    },
+  },
   /** Domain of the Ditto server as a `URL` object, for easily grabbing the `hostname`, etc. */
   get url() {
     return new URL(Conf.localDomain);

src/controllers/api/instance.ts

@@ -53,6 +53,9 @@ const instanceController: AppController = (c) => {
     nostr: {
       pubkey: Conf.pubkey,
       relay: `${wsProtocol}//${host}/relay`,
+      pow: {
+        registrations: Conf.pow.registrations,
+      },
     },
     rules: [],
   });