fix(flutter): make Adjust Window reliable across desktop platforms (#15853)

* fix(flutter): make Adjust Window reliable across desktop platforms

  - Fix incorrect sizing on scaled displays by calculating the target from the
    rendered canvas scale and platform-specific window coordinate units.
  - Fix adjustments using the wrong monitor by querying the current remote
    window's screen, with the main window as fallback.
  - Fix stale geometry after fullscreen or maximized transitions by refreshing
    metrics before calculating and applying the target frame.
  - Fix fullscreen availability checks on Windows and macOS by predicting the
    restored window borders and caching each macOS window's pre-fullscreen work area.
  - Fix incorrect Linux work areas by handling GNOME Wayland fractional scaling
    and caching compositor/X11 work-area measurements when visibleFrame is wrong.
  - Prevent unsafe adjustments by rejecting invalid, oversized, or implausibly
    small target frames.
  - Avoid failures during window teardown by skipping adjustment when the view,
    screen, or native window frame is unavailable.

Signed-off-by: 21pages <sunboeasy@gmail.com>

* fix(flutter): harden Adjust Window handling

  - Use the dynamic Linux resize edge when predicting restored window bounds.
  - Treat GNOME fractional-scaling lookup failures as unknown without repeating
    the lookup for the remote window.
  - Stop adjustment safely when native window calls fail during window teardown.

Signed-off-by: 21pages <sunboeasy@gmail.com>

* fix(flutter): correct Linux monitor selection

Update window_size to use monitor height for vertical bounds, preventing incorrect screen selection with vertically stacked displays.

Signed-off-by: 21pages <sunboeasy@gmail.com>

* docs(flutter): simplify Linux screen handling comments

Keep the source rationale concise and move platform measurements and investigation details out of the implementation.

Signed-off-by: 21pages <sunboeasy@gmail.com>

* fix(flutter): align Adjust Window resize padding

Use the shared drag-to-resize padding for Linux restored-window predictions so menu validation matches the applied frame dimensions.

Signed-off-by: 21pages <sunboeasy@gmail.com>

* fix(flutter): remove Adjust Window screen fallback

Return null when the current window screen is unavailable instead of using the main window's scale factor and work area.

Signed-off-by: 21pages <sunboeasy@gmail.com>

* fix(linux): query Mutter monitor layout mode

  Use DisplayConfig.GetCurrentState instead of inferring scaling from
  experimental features, and handle Ubuntu's UI-scaled logical mode.

Signed-off-by: 21pages <sunboeasy@gmail.com>

* fix(flutter): use native maximized state for Wayland cache

Signed-off-by: 21pages <sunboeasy@gmail.com>

* fix(flutter): allow Adjust Window to fill work area

Signed-off-by: 21pages <sunboeasy@gmail.com>

* fix(flutter): avoid racing screen info updates

Signed-off-by: 21pages <sunboeasy@gmail.com>

* refactor(flutter): remove dead Adjust Window web plumbing

Signed-off-by: 21pages <sunboeasy@gmail.com>

* fix(flutter): tolerate near-unity Wayland scale factors

Signed-off-by: 21pages <sunboeasy@gmail.com>

* fix(flutter): harden window screen detection

Signed-off-by: 21pages <sunboeasy@gmail.com>

* fix(linux): drop deprecated GNOME session detection

Signed-off-by: 21pages <sunboeasy@gmail.com>

* fix(flutter): remove GNOME monitor layout mode flutter cache

Signed-off-by: 21pages <sunboeasy@gmail.com>

---------

Signed-off-by: 21pages <sunboeasy@gmail.com>

src/flutter_ffi.rs

@@ -2655,6 +2655,14 @@ pub fn main_get_common(key: String) -> String {
         return crate::platform::linux::has_gnome_shortcuts_inhibitor_permission().to_string();
         #[cfg(not(target_os = "linux"))]
         return false.to_string();
+    } else if key == "gnome-monitor-layout-mode" {
+        #[cfg(target_os = "linux")]
+        return match crate::platform::linux::gnome_monitor_layout_mode() {
+            Some(mode) => mode.as_str().to_owned(),
+            None => String::new(),
+        };
+        #[cfg(not(target_os = "linux"))]
+        return String::new();
     } else if key == "permanent-password-set" {
         return ui_interface::is_permanent_password_set().to_string();
     } else if key == "local-permanent-password-set" {