Bug : Crash when typing unknown slash command (e.g., /hello)

[deepak0x]

This PR fixes a crash that occurs when a user types an unknown slash command (e.g., /hello) and presses Enter.

Previously, entering a slash command that does not exist in the client-side commands list caused the application to crash with a TypeError. This PR ensures that the client handles unknown slash commands gracefully and aligns behavior with standard Rocket.Chat expectations.

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Steps to Reproduce

1. Open EmbeddedChat.
2. Type /hello (or any unknown slash command) in the chat input.
3. Press Enter.

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Observed Behavior

The application crashes with the following error:

Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'command')
    at CommandsList.js:33
    at HTMLDocument.handleKeyPress (CommandsList.js:54)

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Expected Behavior

• The message /hello should be sent to the server.
• The server should respond with No such command: /hello (standard Rocket.Chat behavior).
• At a minimum, the client should not crash.
• Add a defensive check to ensure selectedItem exists before accessing its properties.

[deepak0x]

hey @vivekyadav-3
you should ask me before raising pr of my issue.... was working on it
it's not good behaviour in open source community🙂