Dismiss dialogs with Ctrl+C in TUI

Improvements

• TerminalKeep /share command available to copy existing share link@kitlangton
• TerminalAdd mode-specific input placeholders to improve context-aware prompts@kitlangton
• TerminalPrevent home wordmark corruption in height-constrained terminals@kitlangton
• DesktopRevert WSL backend mode feature for desktop
• DesktopNotifications enabled on child sessions
• DesktopTerminal PTY buffer now properly carries over between sessions
• DesktopTerminal resize functionality fixed in app