fix(ci): refresh AppImage hashes when Cursor version is unchanged

Cursor can republish the same semver with a new build; the updater
previously skipped prefetch when the version matched, leaving stale
sha256 values. In CI, always re-prefetch and commit when flake.nix drifts.

update-cursor.sh

@@ -111,6 +111,17 @@ is_pointer() {
     [[ "${1:-}" == "latest" || "${1:-}" =~ ^[0-9]+\.[0-9]+$ ]]
 }
 
+is_ci() {
+    [[ -n "${CI:-}" || -n "${GITHUB_ACTIONS:-}" || -n "${GITEA_ACTIONS:-}" ]]
+}
+
+write_version_output() {
+    local value="$1"
+    if [[ -n "${GITHUB_OUTPUT:-}" ]]; then
+        echo "CURSOR_VERSION_INFO=$value" >> "$GITHUB_OUTPUT"
+    fi
+}
+
 # Function to get current version from flake.nix managed block
 get_current_version() {
     awk -v begin="$MANAGED_BEGIN" -v end="$MANAGED_END" '
@@ -296,33 +307,43 @@ main() {
         echo "Resolved: latest=$v_latest pointer($current_track)=$v_current_track pointer($latest_track)=$v_latest_track -> chosen=$target_version"
     fi
     
-    # Check if update is needed
+    # Same semver but Cursor may republish the AppImage (hash/url drift). In CI, always re-prefetch.
     if [[ "$target_version" == "$current_version" ]]; then
-        echo "No update needed. Current version is up to date."
-        if [[ -n "${GITHUB_OUTPUT:-}" ]]; then
-            echo "CURSOR_VERSION_INFO=no_update" >> "$GITHUB_OUTPUT"
+        if is_ci; then
+            echo "Version unchanged ($current_version); re-prefetching URLs and hashes for upstream drift..."
+            update_release "$target_version"
+            rm -f "$FLAKE_FILE.backup"
+            if git diff --quiet -- "$FLAKE_FILE" 2>/dev/null; then
+                echo "Hashes and URLs already match upstream."
+                write_version_output "no_update"
+                exit 0
+            fi
+            test_flake
+            echo "Refreshed hashes for Cursor $target_version"
+            write_version_output "completed:$current_version:$target_version"
+            exit 0
         fi
+        echo "No update needed. Current version is up to date."
+        write_version_output "no_update"
         exit 0
     fi
-    
+
     echo "Update needed: $current_version -> $target_version"
-    
-    # Check if running in CI/GitHub Actions (auto-confirm)
-    if [[ -n "${CI:-}" ]] || [[ -n "${GITHUB_ACTIONS:-}" ]]; then
+
+    if is_ci; then
         echo "Running in CI mode, auto-confirming update..."
         REPLY="y"
     else
         read -p "Do you want to proceed with the update? (y/N): " -n 1 -r
         echo
     fi
-    
+
     if [[ $REPLY =~ ^[Yy]$ ]]; then
         update_release "$target_version"
+        rm -f "$FLAKE_FILE.backup"
         test_flake
         echo "Update completed successfully!"
-        if [[ -n "${GITHUB_OUTPUT:-}" ]]; then
-            echo "CURSOR_VERSION_INFO=completed:$current_version:$target_version" >> "$GITHUB_OUTPUT"
-        fi
+        write_version_output "completed:$current_version:$target_version"
         echo "You can now commit the changes:"
         echo "  git add flake.nix"
         echo "  git commit -m \"Update Cursor to version $target_version\""