feat(config): allow restriction and disabling of uploads

Previously, image uploads were always allowed, unless `CMD_ALLOW_ANONYMOUS=false` and `CMD_ALLOW_ANONYMOUS_EDITS=false`.
This PR adds a new config option `CMD_ENABLE_UPLOADS` to configure image uploads independently. There are three different modes: `all` (everyone can upload, guests too), `registered` (only registered and logged-in users can upload images), and `none` to completely disable image uploads.
The default value is non-breaking as it is `all`, unless the config `CMD_ALLOW_ANONYMOUS=false` and `CMD_ALLOW_ANONYMOUS_EDITS=false` is set, in which case the value is `registered`.
The UI will reflect the setting and either show or hide the upload button.

Signed-off-by: Erik Michelson <github@erik.michelson.eu>

lib/config/default.js

@@ -32,6 +32,7 @@ module.exports = {
   rateLimitNewNotes: 20,
   cookiePolicy: 'lax',
   protocolUseSSL: false,
+  // permissions
   allowAnonymous: true,
   allowAnonymousEdits: false,
   allowFreeURL: false,
@@ -39,6 +40,10 @@ module.exports = {
   disableNoteCreation: false,
   forbiddenNoteIDs: ['robots.txt', 'favicon.ico', 'api', 'build', 'css', 'docs', 'fonts', 'js', 'uploads', 'vendor', 'views'],
   defaultPermission: 'editable',
+
+  enableUploads: undefined, // 'all', 'registered', 'none' are valid options.
+  // This is undefined by default and set during runtime based on allowAnonymous and allowAnonymousEdits for backwards-compatibility unless explicitly set.
+
   dbURL: '',
   db: {},
   // ssl path