Consume Ctrl+click after opening a URL so it isn't opened twice

[aaronmhmr]

What

On a Ctrl+click on a URL, on_buttonpress opens the link but never returns True, so GTK keeps propagating the button-press-event. With mouse reporting enabled, VTE forwards the same click to the foreground application. TUIs that treat Ctrl+click as "open link" (e.g. Claude Code, and comparable vim/tmux mouse setups) then open the same URL a second time, producing two browser tabs from a single click.

This returns True once a URL has actually been opened, so Terminator consumes the click it just handled. Clicks that don't hit a URL still fall through unchanged (selection, etc. are unaffected).

Why it happens

terminatorlib/terminal.py, on_buttonpress, MOUSEBUTTON_LEFT branch — the two paths that call open_url() fall through without stopping the event, so the click reaches both Terminator's URL handler and the application underneath.

Evidence

Pointing the default http(s) handler at a logging wrapper, a single Ctrl+click:

• in a normal shell (no mouse reporting): 1 browser launch ✅
• inside a mouse-reporting TUI: 2 launches ~0.5s apart — one from Terminator, one from the app ❌

With this change, the mouse-reporting case drops back to a single launch.

Fixes #1103

🤖 Generated with Claude Code