Support 'did you mean?' for nested subcommand typos

[stalep]

Summary

Follow-up to #561. The CommandNotFoundHandler is now called with the unknown command name and available commands for top-level command-not-found errors. However, it is not called when a nested subcommand is not found (e.g., alias ad instead of alias add).

Problem

When a group command receives an invalid subcommand, the parser generates a CommandLineParserException (not CommandNotFoundException):

// AeshCommandLineParser.java:576-578
processedCommand.addParserException(new CommandLineParserException(
    "'" + command + " " + iterator.peekWord()
    + "' is not part of the " + command + " commands. See '" + command + " --help'."));

The CommandNotFoundHandler is only invoked for CommandNotFoundException, so nested subcommand typos bypass the handler entirely.

Use case

$ jbang alis add myalias test.java
jbang: 'alis' is not a jbang command. Did you mean 'alias'?  <-- works (#561)

$ jbang alias ad myalias test.java
'alias ad' is not part of the alias commands.  <-- no "did you mean?" suggestion

The second case should suggest add since the child parser knows its available subcommands (add, list, remove).

Proposed approach

At the parser level (AeshCommandLineParser.parse() line 576-578), the unknown subcommand name and the available child parser names are both accessible:

• Unknown name: iterator.peekWord()
• Available children: getAllChildParsers() -> each child's getProcessedCommand().name()

Options:

1. Throw CommandNotFoundException instead of CommandLineParserException for invalid subcommands -- this would route through the existing handler. But it changes exception semantics and may break catch blocks that distinguish these types.
2. Store the unknown subcommand + available names on the ProcessedCommand and check for it in the runtime/runner error handling paths.
3. Call the handler directly from the parser exception path -- add handler invocation to the CommandLineParserException catch block in ReadlineConsole, AeshCommandRuntime, and AeshRuntimeRunner.
4. Include available subcommand names in the parser exception message -- less flexible but simpler.

Depends on

• CommandNotFoundHandler: pass unknown command name and available commands to handler #561 (enhanced CommandNotFoundHandler with unknownCommand + availableCommands)

Environment

• aesh 3.17-dev (master)