fix(input): separate copy and paste event listeners (@yasith-tharuka)

[yasith-tharuka]

Description

• Fixed copy and paste event listeners in frontend/src/ts/input/listeners/misc.ts. Previously, addEventListener("copy paste", ...) and addEventListener("select selectstart", ...) were used, but browsers treat space-separated strings as single unknown event names, preventing the handlers from firing.
• Separated copy and paste into independent addEventListener calls with preventDefault().
• Removed the dead select selectstart listener block since caret positioning is already handled by selectionchange.

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Closes #8361

[Copilot]

Pull request overview

Fixes broken copy/paste prevention on the hidden words input by registering real DOM event types (space-separated strings were treated as one unknown event name, so handlers never fired).

Changes:

• Split "copy paste" into separate "copy" + "paste" addEventListener registrations.
• Removed the dead "select selectstart" listener block (caret/selection handling already done via selectionchange).

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