move theme to site settings and make default_theme apply when logged out

config.maple

···
 instance = {
 	name = 'beep'
 	welcome = 'welcome to beep!'
+
+	default_theme = 'https://cdn.jsdelivr.net/npm/@picocss/pico@2/css/pico.classless.min.css'
+	allow_changing_theme = true
 }
 
 http = {
···
 	bio_min_len = 0
 	bio_max_len = 200
 	bio_pattern = '(.|\s)*'
-
-	default_theme = 'https://cdn.jsdelivr.net/npm/@picocss/pico@2/css/pico.classless.min.css'
-	allow_changing_theme = true
 }

src/api.v

···
 		password_salt: salt
 	}
 
-	if app.config.user.default_theme != '' {
-		user.theme = app.config.user.default_theme
+	if app.config.instance.default_theme != '' {
+		user.theme = app.config.instance.default_theme
 	}
 
 	sql app.db {
···
 
 @['/api/user/set_theme'; post]
 fn (mut app App) api_user_set_theme(mut ctx Context, url string) veb.Result {
-	if !app.config.user.allow_changing_theme {
+	if !app.config.instance.allow_changing_theme {
 		ctx.error('this instance disallows changing themes :(')
 		return ctx.redirect('/me')
 	}

src/config.v

···
 	static_path string
 	instance struct {
 	pub mut:
-		name    string
-		welcome string
+		name                 string
+		welcome              string
+		default_theme        string
+		allow_changing_theme bool
 	}
 	http struct {
 	pub mut:
···
 	}
 	user struct {
 	pub mut:
-		username_min_len     int
-		username_max_len     int
-		username_pattern     string
-		nickname_min_len     int
-		nickname_max_len     int
-		nickname_pattern     string
-		password_min_len     int
-		password_max_len     int
-		password_pattern     string
-		pronouns_min_len     int
-		pronouns_max_len     int
-		pronouns_pattern     string
-		bio_min_len          int
-		bio_max_len          int
-		bio_pattern          string
-		default_theme        string
-		allow_changing_theme bool
+		username_min_len int
+		username_max_len int
+		username_pattern string
+		nickname_min_len int
+		nickname_max_len int
+		nickname_pattern string
+		password_min_len int
+		password_max_len int
+		password_pattern string
+		pronouns_min_len int
+		pronouns_max_len int
+		pronouns_pattern string
+		bio_min_len      int
+		bio_max_len      int
+		bio_pattern      string
 	}
 }
 
···
 	loaded_instance := loaded.get('instance')
 	config.instance.name = loaded_instance.get('name').to_str()
 	config.instance.welcome = loaded_instance.get('welcome').to_str()
+	config.instance.default_theme = loaded_instance.get('default_theme').to_str()
+	config.instance.allow_changing_theme = loaded_instance.get('allow_changing_theme').to_bool()
 
 	loaded_http := loaded.get('http')
 	config.http.port = loaded_http.get('port').to_int()
···
 	config.user.bio_min_len = loaded_user.get('bio_min_len').to_int()
 	config.user.bio_max_len = loaded_user.get('bio_max_len').to_int()
 	config.user.bio_pattern = loaded_user.get('bio_pattern').to_str()
-	config.user.default_theme = loaded_user.get('default_theme').to_str()
-	config.user.allow_changing_theme = loaded_user.get('allow_changing_theme').to_bool()
 
 	return config
 }

src/templates/partial/header.html

···
 	@include 'assets/style.html'
 	@if ctx.is_logged_in() && user.theme != none
 	<link rel="stylesheet" href="@user.get_theme()">
+	@else if app.config.instance.default_theme != ''
+	<link rel="stylesheet" href="@app.config.instance.default_theme">
 	@endif
 </head>
 

src/templates/user.html

···
 	<form action="/api/user/set_nickname" method="post">
 		<input type="submit" value="reset nickname">
 	</form>
-	@if app.config.user.allow_changing_theme
+	@if app.config.instance.allow_changing_theme
 	<br>
 	<form action="/api/user/set_theme" method="post">
 		<label for="url">theme:</label>