Fix duplicate class and annotation placement lint errors

Classes contributed to by more than one file now carry the `partial`
attribute. trains.lua declared its command as `ExpCommand_Artillery`,
which was a copy paste.

`Color.0` and `MapPosition.0` became `.struct` in fmtk 2.1.6.

emmylua rejects `@type` on a function statement or a `do` block, so
those are moved onto the local or replaced by `@param` and `@return`.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

exp_commands/module/commands/authorities.lua

@@ -10,7 +10,7 @@ The default permission authorities controlled by the flags: admin_only, system_o
 
 local Storage = require("modules/exp_util/storage")
 
-local Commands = require("modules/exp_commands") --- @class Commands
+local Commands = require("modules/exp_commands") --- @class (partial) Commands
 local add, allow, deny = Commands.add_permission_authority, Commands.status.success, Commands.status.unauthorised
 
 local authorities = {}

exp_commands/module/commands/rcon.lua

@@ -12,7 +12,7 @@ local ExpUtil = require("modules/exp_util")
 local Async = require("modules/exp_util/async")
 local Storage = require("modules/exp_util/storage")
 
-local Commands = require("modules/exp_commands") --- @class Commands
+local Commands = require("modules/exp_commands") --- @class (partial) Commands
 
 local rcon_env = {} --- @type table<string, any>
 local rcon_static = {} --- @type table<string, any>

exp_commands/module/commands/types.lua

@@ -25,7 +25,7 @@ local Commands = require("modules/exp_commands")
 local add, parse = Commands.add_data_type, Commands.parse_input
 local valid, invalid = Commands.status.success, Commands.status.invalid_input
 
-local types = {} --- @class Commands.types
+local types = {} --- @class (partial) Commands.types
 
 --- A boolean value where true is one of: yes, y, true, 1
 types.boolean =