[FEAT] More convenient large image navigation via mouse wheel

[cmixed]

Is your feature request related to a problem? Please describe.
QuickView has already added keyboard-based panning with customizable step sizes, and I must express my highest respect for that. Compared to earlier versions, the large image viewing experience has improved significantly. However, for prolonged viewing sessions — especially when zooming in and out to inspect details — it still isn't quite there yet. Two or more key combinations for frequent panning and image comparison are still too cumbersome. Even with customizable keys, the scroll wheel remains underutilized, which is arguably the best input method for image navigation.

Describe the solution you'd like
Add an optional setting in Preferences (e.g., "Use scroll wheel for panning when image exceeds window") so users who don't need it can keep the current behavior — I understand large-image wheel panning isn't something everyone uses (but I use it heavily :-( ).

When the image is larger than the window:

1. Scroll wheel — pan up/down (speed synced with Keyboard Pan Step settings)
2. Shift + scroll wheel — pan left/right (same speed sync)
3. Ctrl + scroll wheel — keep zoom behavior unchanged

When the image is in "Fit to Window" mode or otherwise smaller than the QuickView window, the scroll wheel reverts to its normal function: switching between images.

Or more intuitively: whenever the minimap appears, the wheel pans; when the minimap is absent, the wheel switches images.

Technical Note (Optional)

1. The existing Keyboard Pan Step (Normal/Fast) values could be reused for wheel pan speed.
2. The minimap visibility state already serves as a clear indicator of whether panning is possible, making it a natural trigger for this behavior toggle.

And, my thanks.

Additional context
The developer may refer to Bandiview, a professional image viewer I currently use as a supplement. It is also an excellent piece of software and could serve as a reference for feature parity.

[bananakid]

I support this request, except I think it should strictly do it's thing (pan when image is larger then the window) or do nothing (if image is smaller than the window). Because complicated script-like actions are less intuitive and may conflict with other hotkey/keyboard input settings. Perhaps, doing something in both scenarios may be an additional option.

[cmixed]

I support this request, except I think it should strictly do it's thing (pan when image is larger then the window) or do nothing (if image is smaller than the window). Because complicated script-like actions are less intuitive and may conflict with other hotkey/keyboard input settings. Perhaps, doing something in both scenarios may be an additional option.

That's true — this does introduce a new state users need to be aware of. That's exactly why I suggested adding a toggle. But I don't think we should handle both scenarios; that would degrade the existing UX rather than improve it, and it'd be a maintenance headache too.

I get that it's a bit more complex logically, but in practice it feels very intuitive. (Though I'll admit I'm used to this workflow, so I'm probably biased.)

By default, QuickView opens in fit-to-screen mode. When you zoom in, you're usually trying to examine that specific image in more detail — not switch to another one. In that case, panning with the scroll wheel is super convenient. When you switch back to fit-to-screen, you can just use the wheel to browse through images. Or use the keyboard shortcuts for next/previous image.

One more thought: it would be great to add a middle-click to fit-to-screen option. That way, switching back from a zoomed-in view is as simple as a single middle-click, and then you can immediately use the scroll wheel to browse through images again. Much more convenient and intuitive.****