feat(cli): support chaining multiple commands with ;

[bouclem]

Closes #61.

Adds support for chaining multiple commands in a single line (or single invocation) using ; as a separator. Works the same way in both interactive mode and when passing args directly:

> setup 1.2.5; decompile; build

java -jar RetroMCP.jar setup 1.2.5 ";" decompile

The separator can be a standalone token (";") or attached to a previous token (1.2.5;).

Behavior

• Commands run in order
• If a command fails (unknown command, task returned error), the rest of the queue is dropped with a warning, similar to shell && semantics
• exit mid-chain stops execution as before
• Empty segments (e.g. setup ;; decompile) are skipped silently
• Single commands behave identically to today

Implementation

• Pulled the per-command logic in MainCLI's constructor into a queue-based loop
• Added two small helpers: splitCommands(String[]) for tokenizing by ; and readInteractiveCommands() for the interactive prompt
• No changes to parseArg, setMode, setParams, or any task code

Testing

• gradlew build passes
• Verified help; help setup; exit chains correctly in interactive mode
• Verified help ";" "help" "setup" chains correctly via CLI args
• Verified bogus_cmd; help; exit aborts the rest after the unknown command
• No behavioral change for users running single commands