fix(display): enforce at least one real monitor in profile application (#3106)

ensureEnabledOutput previously checked if ANY output was enabled,
including virtual fallback outputs. A profile with eDP-1 disabled and
FALLBACK enabled was treated as valid, causing the only real monitor
to be turned off during hotplug transitions.

Now ensureEnabledOutput only considers outputs with make+model (real
monitors) when checking for enabled outputs. When all real outputs are
disabled, it enables the first real one. When no real outputs exist in
the profile at all, applyConfigEntry writes an empty config and lets
the compositor handle fallback via its built-in default rules.

Fixes the case where unplugging an external monitor leaves the laptop
display disabled because a stale FALLBACK auto-profile was applied.

quickshell/Modules/Settings/DisplayConfig/DisplayConfigState.qml

@@ -530,11 +530,20 @@ Singleton {
         const outputKeys = Object.keys(configEntry.outputs || {});
         if (outputKeys.length === 0)
             return false;
-        const hasEnabled = outputKeys.some(k => !configEntry.outputs[k].disabled);
-        if (hasEnabled)
+        const hasEnabledReal = outputKeys.some(k => {
+            const o = configEntry.outputs[k];
+            return !o.disabled && o.make && o.model;
+        });
+        if (hasEnabledReal)
             return false;
-        delete configEntry.outputs[outputKeys[0]].disabled;
-        return true;
+        for (const k of outputKeys) {
+            const o = configEntry.outputs[k];
+            if (o.make && o.model) {
+                delete o.disabled;
+                return true;
+            }
+        }
+        return false;
     }
 
     function applyConfigEntry(configEntry, configId, profileName, isManual) {
@@ -548,6 +557,20 @@ Singleton {
             return;
         }
         ensureEnabledOutput(configEntry);
+        const outputKeys = Object.keys(configEntry.outputs || {});
+        const hasRealOutput = outputKeys.some(k => {
+            const o = configEntry.outputs[k];
+            return o.make && o.model;
+        });
+        if (!hasRealOutput) {
+            backendWriteOutputsConfig({}, null, success => {
+                if (success) {
+                    SettingsData.setActiveDisplayProfile(CompositorService.compositor, configId);
+                    WlrOutputService.requestState();
+                }
+            });
+            return;
+        }
         // Capture the entry being applied so disabled-output settings fields can read
         // scale/position/transform back even when wlr reports no logical viewport.
         root.lastAppliedEntry = JSON.parse(JSON.stringify(configEntry));