/signcopy throws when not using quotes

### CraftBook Version

5.0.0-SNAPSHOT

### Platform Version

26.1.2-60-main@b4682bf

### Confirmations

- [x] I am using the most recent Minecraft release.
- [x] I am using a version of WorldEdit compatible with my Minecraft version.
- [x] I am using a version of CraftBook compatible with my Minecraft version.
- [x] I am using the latest or recommended version of my platform software.
- [x] I am NOT using a hybrid server, e.g. a server that combines Bukkit and Forge. Examples include Arclight, Mohist, and Cardboard.
- [x] I am NOT using a fork of WorldEdit, such as FastAsyncWorldEdit (FAWE) or AsyncWorldEdit (AWE)

### Bug Description

Not enclosing the line-content parameter of the `/signcopy`-command throws an exception.

```
[07:50:03 ERROR]: [org.enginehub.craftbook.PlatformCommandManager] An unexpected error while handling a CraftBook command
java.lang.IllegalStateException: Too many values present
at com.google.common.base.Preconditions.checkState(Preconditions.java:513) ~[guava-33.5.0-jre.jar:?]
at worldedit-bukkit-8.0.0-SNAPSHOT-dist.jar//org.enginehub.piston.CommandValue.asSingle(CommandValue.java:109) ~[?:?]
at craftbook-bukkit-5.0.0-SNAPSHOT-dist.jar//org.enginehub.craftbook.mechanics.signcopier.SignEditCommandsRegistration.extract$text(SignEditCommandsRegistration.java:153) ~[?:?]
at craftbook-bukkit-5.0.0-SNAPSHOT-dist.jar//org.enginehub.craftbook.mechanics.signcopier.SignEditCommandsRegistration.cmd$edit(SignEditCommandsRegistration.java:119) ~[?:?]
at worldedit-bukkit-8.0.0-SNAPSHOT-dist.jar//org.enginehub.piston.CommandManager.execute(CommandManager.java:157) ~[?:?]
at craftbook-bukkit-5.0.0-SNAPSHOT-dist.jar//org.enginehub.craftbook.PlatformCommandManager.handleCommand(PlatformCommandManager.java:157) ~[?:?]
at craftbook-bukkit-5.0.0-SNAPSHOT-dist.jar//org.enginehub.craftbook.bukkit.CraftBookPlugin.onCommand(CraftBookPlugin.java:251) ~[?:?]
at worldedit-bukkit-8.0.0-SNAPSHOT-dist.jar//com.sk89q.bukkit.util.DynamicPluginCommand.execute(DynamicPluginCommand.java:55) ~[?:?]
at io.papermc.paper.command.brigadier.bukkit.BukkitCommandNode$BukkitBrigCommand.run(BukkitCommandNode.java:83) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at com.mojang.brigadier.context.ContextChain.runExecutable(ContextChain.java:73) ~[brigadier-1.3.10.jar:?]
at net.minecraft.commands.execution.tasks.ExecuteCommand.execute(ExecuteCommand.java:30) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.commands.execution.tasks.ExecuteCommand.execute(ExecuteCommand.java:13) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.commands.execution.UnboundEntryAction.lambda$bind$0(UnboundEntryAction.java:8) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.commands.execution.CommandQueueEntry.execute(CommandQueueEntry.java:5) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.commands.execution.ExecutionContext.runCommandQueue(ExecutionContext.java:104) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.commands.Commands.executeCommandInContext(Commands.java:469) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.commands.Commands.performCommand(Commands.java:377) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.commands.Commands.performCommand(Commands.java:365) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.server.network.ServerGamePacketListenerImpl.performUnsignedChatCommand(ServerGamePacketListenerImpl.java:2426) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.server.network.ServerGamePacketListenerImpl.lambda$handleChatCommand$0(ServerGamePacketListenerImpl.java:2399) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.server.TickTask.run(TickTask.java:18) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.util.thread.BlockableEventLoop.doRunTask(BlockableEventLoop.java:205) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:24) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:1569) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:194) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:179) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.server.MinecraftServer.pollTaskInternal(MinecraftServer.java:1549) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.server.MinecraftServer.pollTask(MinecraftServer.java:1543) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.server.MinecraftServer.recordTaskExecutionTimeWhileWaiting(MinecraftServer.java:1273) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1389) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:304) ~[paper-26.1.2.jar:26.1.2-60-b4682bf]
at java.base/java.lang.Thread.run(Thread.java:1474) ~[?:?]
```

### Expected Behavior

In the worst case, print a proper error - but to be frank, I'd rather have the plugin simply collect the arguments without requiring enclosing quotes, as it is obvious that that's what the player wants, based on the fact that it is the last parameter - no ambiguity there. In general, having to use said quotes is a big confusion to many of our players.

### Reproduction Steps

1. Copy a sign
2. Run `/signcopy edit 1 first second`

### Anything Else?

_No response_