Add SteamWar CLI module

- add Clikt-based `sw` entrypoint and subcommands
- include database, user, dev, and profiler commands
- wire CLI build and CI install/release steps

CLI/src/commands/database/DatabaseCommand.kt

@@ -0,0 +1,22 @@
+package de.steamwar.commands.database
+
+import com.github.ajalt.clikt.core.CliktCommand
+import com.github.ajalt.clikt.core.CliktError
+import com.github.ajalt.clikt.core.Context
+import com.github.ajalt.clikt.core.findOrSetObject
+import com.github.ajalt.clikt.parameters.options.flag
+import com.github.ajalt.clikt.parameters.options.option
+import de.steamwar.db.Database
+
+class DatabaseCommand: CliktCommand(name = "db") {
+    val useProduction by option().flag()
+    val db by findOrSetObject { Database }
+
+    override fun help(context: Context): String = "Run database commands"
+
+    override fun run() {
+        if (!useProduction && db.database == "production") {
+            throw CliktError("You should not use the production database!")
+        }
+    }
+}