hermes - 💡(How to fix) Fix [Bug]: Dashboard Chat context-menu copy does not bridge xterm selection to clipboard

Bug description

In the Dashboard Chat web TUI (hermes dashboard --tui), browser/context-menu copy is not explicitly bridged from xterm's internal selection to the browser clipboard.

Current main has keyboard-specific copy handling, but there does not appear to be a host-level DOM copy listener on the xterm host that reads term.getSelection() and writes it to event.clipboardData. As a result, even when xterm text selection exists, using the browser context menu / browser menu copy path may fail or not copy the selected terminal text.

Expected behavior

If the user selects text inside the Dashboard Chat terminal and chooses browser/context-menu copy, the selected xterm text should be copied to the browser/system clipboard.

Actual behavior

Browser/context-menu copy is not reliably connected to xterm's internal selection. Copy may fail or copy something other than the selected terminal text.

Scope notes

• This is separate from broad mouse-selection enablement. Current main already includes selection/mouse-tracking mitigations such as macOptionClickForcesSelection, rightClickSelectsWord, and dashboard PTY mouse disabling.
• This is also separate from bare Ctrl+C semantics. Bare Ctrl+C should not be hijacked on Windows/Linux terminal-like embeds unless intentionally redesigned, because users may expect terminal interrupt/cancel behavior.
• Related paste issue: #24860.
• Related PR: #29975.

Environment where observed during original investigation

• Hermes Dashboard Chat web TUI
• Hermes running in Docker/WSL on Windows 10
• Chrome browser accessing the dashboard

The proposed/current PR fix is environment-neutral: install a host-level DOM copy event listener scoped only to the Dashboard Chat xterm host, and only handle it when term.getSelection() is non-empty.