Address review on exp_server_list

The controller and instance plugins are init functions with closures.
The controller batches refreshes with setMany and deleteMany, and the
instance gates updates on its status instead of a started flag.

short_name is now display_name. New always_on_top field sorts servers
first in get_servers. The record carries has_password from the game
password in factorio.settings, never the password itself, and the
description falls back to the one in factorio.settings. A controller
welcome is used when the instance has none, and the readme falls back
to a default welcome from the locale.

Lua gets is_synced for connect.lua. The readme passes an empty detail
instead of nil to the join tooltip so the player count stays in __2__,
restores the Password status, shows the welcome title as a centered
label and shortens long descriptions with the full text as a tooltip.

The Lua tests assert the lookups they index, which fixes the lint.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

exp_server_list/module/control.lua

@@ -3,7 +3,7 @@ The details of every instance in the cluster, kept up to date by the controller.
 
 The instance plugin sends the whole list when the server starts and each
 changed server after that. Hidden servers are kept but left out of
-get_servers and find_servers.
+get_servers and find_servers. Servers which are always on top come first.
 
 local ExpServerList = require("modules/exp_server_list")
 
@@ -19,11 +19,13 @@ local Storage = require("modules/exp_util/storage")
 --- @class ExpServerList.Server
 --- @field id number The instance id
 --- @field name string
---- @field short_name string The name when not set
---- @field description string
---- @field welcome string
+--- @field display_name string The name when not set
+--- @field description string The server description when not set
+--- @field welcome string The controller welcome when not set, can still be empty
 --- @field reset_time string
 --- @field hidden boolean
+--- @field always_on_top boolean
+--- @field has_password boolean
 --- @field mod_pack_name string
 --- @field factorio_version string Empty if it has never started
 --- @field player_count number
@@ -55,10 +57,13 @@ end)
 --- @param a ExpServerList.Server
 --- @param b ExpServerList.Server
 local function by_name(a, b)
+    if a.always_on_top ~= b.always_on_top then
+        return a.always_on_top
+    end
     return a.name < b.name
 end
 
---- Get every server that is not hidden, sorted by name
+--- Get every server that is not hidden, those always on top first then by name
 --- @return ExpServerList.Server[]
 function ExpServerList.get_servers()
     local rtn, count = {}, 0
@@ -79,20 +84,26 @@ function ExpServerList.get_server(server_id)
     return servers[server_id]
 end
 
+--- True once the controller has sent the list
+--- @return boolean
+function ExpServerList.is_synced()
+    return current.id ~= nil
+end
+
 --- Get this server, nil until the controller has sent the list
 --- @return ExpServerList.Server?
 function ExpServerList.get_current()
     return current.id and servers[current.id]
 end
 
---- Get the servers that are not hidden whose name, short name or id contains the search, sorted by name
+--- Get the servers that are not hidden whose name, display name or id contains the search, sorted like get_servers
 --- @param search string
 --- @return ExpServerList.Server[]
 function ExpServerList.find_servers(search)
     search = search:lower()
     local rtn, count = {}, 0
     for _, server in ipairs(ExpServerList.get_servers()) do
-        local str = server.name .. " " .. server.short_name .. " " .. server.id
+        local str = server.name .. " " .. server.display_name .. " " .. server.id
         if str:lower():find(search, 1, true) then
             count = count + 1
             rtn[count] = server