Make paste UI optimistically enabled on web when Web Clipboard API is available

Clipboard.has() now returns true on web when the Web Clipboard API is
available, even if the in-memory clipboard doesn't have matching content.
This ensures paste buttons and menu items are enabled when the system
clipboard might contain valid GDevelop content from another tab.

Also update hasClipboardEvents/Conditions/Actions() to return true
optimistically when the in-memory clipboard is empty but the Web
Clipboard API is available.

All paste operations already handle invalid/missing content gracefully
via Clipboard.read(), so enabling paste unconditionally is safe.

https://claude.ai/code/session_014Tphwia3UUUdis3TUsRffE

Author: claude

newIDE/app/src/EventsSheet/ClipboardKind.js

@@ -23,6 +23,9 @@ export const CLIPBOARD_KIND = 'EventsAndInstructions';
 export const hasClipboardEvents = () => {
   if (!Clipboard.has(CLIPBOARD_KIND)) return false;
   const clipboardContent = Clipboard.get(CLIPBOARD_KIND);
+  // If in-memory clipboard has no content but has() returned true,
+  // it means Web Clipboard API is available and might have content.
+  if (clipboardContent === null) return true;
   const eventsCount = SafeExtractor.extractNumberProperty(
     clipboardContent,
     'eventsCount'
@@ -35,6 +38,9 @@ export const hasClipboardEvents = () => {
 export const hasClipboardConditions = () => {
   if (!Clipboard.has(CLIPBOARD_KIND)) return false;
   const clipboardContent = Clipboard.get(CLIPBOARD_KIND);
+  // If in-memory clipboard has no content but has() returned true,
+  // it means Web Clipboard API is available and might have content.
+  if (clipboardContent === null) return true;
   const conditionsCount = SafeExtractor.extractNumberProperty(
     clipboardContent,
     'conditionsCount'
@@ -47,6 +53,9 @@ export const hasClipboardConditions = () => {
 export const hasClipboardActions = () => {
   if (!Clipboard.has(CLIPBOARD_KIND)) return false;
   const clipboardContent = Clipboard.get(CLIPBOARD_KIND);
+  // If in-memory clipboard has no content but has() returned true,
+  // it means Web Clipboard API is available and might have content.
+  if (clipboardContent === null) return true;
   const actionsCount = SafeExtractor.extractNumberProperty(
     clipboardContent,
     'actionsCount'

newIDE/app/src/Utils/Clipboard.js

@@ -63,19 +63,36 @@ export default class Clipboard {
    * Quickly check that the clipboard content *should* be containing valid JSON content
    * of the specified kind.
    *
-   * This is a synchronous check against the in-memory clipboard (or Electron clipboard).
-   * It does NOT read the system clipboard (which is async on the web).
-   * Use `Clipboard.read` for a full async read that checks the system clipboard.
+   * On Electron, this is a synchronous check against the system clipboard.
+   * On the web, this checks the in-memory clipboard first. If nothing is found
+   * but the Web Clipboard API is available, it optimistically returns true
+   * because the system clipboard might contain valid content from another tab.
+   * Paste operations use `Clipboard.read` which handles invalid content gracefully.
    */
   static has(kind: ClipboardKind): boolean {
-    let text = '';
     if (electronClipboard) {
-      text = electronClipboard.readText();
-    } else {
-      text = internalClipboard;
+      return (
+        electronClipboard.readText().indexOf(mangleClipboardKind(kind)) === 12
+      );
+    }
+
+    // Check in-memory clipboard first.
+    if (internalClipboard.indexOf(mangleClipboardKind(kind)) === 12) {
+      return true;
+    }
+
+    // If Web Clipboard API is available, the system clipboard might contain
+    // valid content from another tab — optimistically return true.
+    // Paste operations use Clipboard.read() which handles invalid content gracefully.
+    if (
+      typeof navigator !== 'undefined' &&
+      navigator.clipboard &&
+      navigator.clipboard.readText
+    ) {
+      return true;
     }
 
-    return text.indexOf(mangleClipboardKind(kind)) === 12; /// 12 is the position of '000kind' value
+    return false;
   }
 
   /**