Add CloseAll and CloseAllOthers as bindable mouse actions

[nynjapirate]

What

Adds two new entries to the MouseAction enum and _performMouseAction dispatcher:

• CloseAll (41) — close every window of the application this button represents.
• CloseAllOthers (42) — close every window of the application except the one the action was invoked on.

Both are then surfaced in all seven MouseAction dropdowns in settings-schema.json (left/middle/right click on the windowlist button, three thumbnail-window mouse-button actions, and the adv-mouse-list action picker), so a user can bind e.g. Shift + Middle on a windowlist button to "Close all others."

Why

These two actions already exist as right-click menu items but aren't bindable. Power users who set up custom mouse/keyboard combos in the Advanced tab have asked for them.

How

The dispatcher cases are direct ports of the existing right-click menu callbacks (the Close others / Close all items in _populateContextMenu). Same window-iteration logic for the three button shapes:

• Grouped button (this.getNumberOfWindow() > 1) — iterate this._windows.
• Ungrouped, sibling buttons exist (btns.length > 1) — iterate btns[i]._currentWindow.
• Single window — degenerate; CloseAll closes the one window, CloseAllOthers is a silent no-op.

Existing _performMouseAction call sites all pass a meaningful window argument (either this._metaWindow from thumbnail menus or this._currentWindow from windowlist buttons), so CloseAllOthers correctly spares the window the user invoked the action on — whether that's via a thumbnail or the button itself.

File-level notes

• 6.0/applet.js is a symlink to ../5.4/applet.js, so the patch only edits 4.0/applet.js and 5.4/applet.js.
• settings-schema.json is a real file in each of 4.0/, 5.4/, 6.0/ — all three updated.
• po/CassiaWindowList@klangman.pot regenerated via ./makepot. The diff is larger than the rest of the patch because the previous .pot was missing several schema-derived strings (Tile left, Untile window, etc); makepot swept them in along with the two new feature msgids (Close all, Close all others). Happy to drop the .pot from the commit if you'd prefer to regenerate yourself at merge time.

Test plan

• Tested locally on Cinnamon 6.0 by binding Shift + Middle → Close all and Ctrl + Middle → Close all others via the Advanced tab; verified both fire correctly with two terminal windows open in grouped and ungrouped modes.
• Verified the existing right-click Close all / Close others menu items still work unchanged.
• Verified node --check is clean on the patched applet.js files and the three settings-schema.json files parse as valid JSON.

Thank you for creating Cassia — you have been super awesome and responsive and your applet is something I stare at every day... so when I got the opportunity to have a little time with a coding ai (I'm no coder myself..,. yet) I thought I'd throw this your way as a small thank you. Cheers!

P.S. If it is trash and I totally missed something about why this was unhelpful, not needed or anything else I am all ears.

[klangman]

Thanks for the code.. I'll take a look at it over the next week or so. My main dev machine is currently down after an OS upgrade gone wrong so I have to get that back up and running before I can do much else.

Regarding the pot files. I have not been updating them here on my repo since the pots get updated by a script when I move the changes to the Linux Mint Cinnamon Spices repo anyhow.

Over all I think this is a good idea, but it is a bit dangerous that you can close a large set of applications with a mistaken key+click. But this window-list is meant for power users and users would have to select this behavior (i.e it is not the default) so I guess its fine.

Thanks again!