feat: Fixes release build failures and get's release dockerfile working.

Sources/ViewControllerLive/Views/Utils/Buttons.swift

@@ -2,7 +2,8 @@ import Elementary
 import SharedModels
 import URLRouting
 
-struct ToggleFormButton: HTML {
+// TODO: Remove.
+struct ToggleFormButton: HTML, Sendable {
   var content: some HTML<HTMLTag.a> {
     a(.href("javascript:void(0)"), .on(.click, "toggleContent('form')"), .class("btn-add")) {
       "+"
@@ -12,20 +13,24 @@ struct ToggleFormButton: HTML {
 
 enum Button {
 
+  @Sendable
   static func add() -> some HTML<HTMLTag.button> {
     button(.class("btn btn-add")) { "+" }
   }
 
+  @Sendable
   static func danger<C: HTML>(@HTMLBuilder body: () -> C) -> some HTML<HTMLTag.button> {
     button(.class("danger")) { body() }
   }
 
+  @Sendable
   static func close(id: String, resetURL: String? = nil) -> some HTML<HTMLTag.button> {
     button(.class("btn-close"), .on(.click, makeOnClick(id, resetURL))) {
       "x"
     }
   }
 
+  @Sendable
   static func close(id: IDKey, resetURL route: ViewRoute? = nil) -> some HTML<HTMLTag.button> {
     close(
       id: id.description,
@@ -33,16 +38,19 @@ enum Button {
     )
   }
 
+  @Sendable
   static func update() -> some HTML<HTMLTag.button> {
     button(.class("btn-update")) { "Update" }
   }
 
+  @Sendable
   static func detail() -> some HTML<HTMLTag.button> {
     button(.class("btn-detail")) {
       "〉"
     }
   }
 
+  @Sendable
   private static func makeOnClick(_ id: String, _ resetURL: String?) -> String {
     let output = "toggleContent('\(id)');"
     if let resetURL {