fix: remove Node.js from actual path location on Act runner

The Act runner has Node 18 at /opt/acttoolcache/node/18.20.3/x64/bin/,
not at /usr/local/bin/. Use $(dirname "$(which node)") to find and
remove the actual binary location before installing Node 22.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitea/workflows/build-app.yml

@@ -25,9 +25,12 @@ jobs:
           NEED_INSTALL=false
           if command -v node >/dev/null 2>&1; then
             NODE_MAJOR=$(node --version | sed 's/v\([0-9]*\).*/\1/')
-            echo "Found Node.js $(node --version) (major: ${NODE_MAJOR})"
+            OLD_NODE_DIR=$(dirname "$(which node)")
+            echo "Found Node.js $(node --version) at $(which node) (major: ${NODE_MAJOR})"
             if [ "$NODE_MAJOR" -lt 22 ]; then
-              echo "Node.js ${NODE_MAJOR} is too old, upgrading to 22..."
+              echo "Node.js ${NODE_MAJOR} is too old, removing before installing 22..."
+              sudo rm -f "${OLD_NODE_DIR}/node" "${OLD_NODE_DIR}/npm" "${OLD_NODE_DIR}/npx" "${OLD_NODE_DIR}/corepack"
+              hash -r
               NEED_INSTALL=true
             fi
           else
@@ -37,7 +40,9 @@ jobs:
           if [ "$NEED_INSTALL" = true ]; then
             curl -fsSL https://deb.nodesource.com/setup_22.x | sudo -E bash -
             sudo apt-get install -y nodejs
+            hash -r
           fi
+          echo "Node.js at: $(which node)"
           node --version
           npm --version
 
@@ -97,7 +102,7 @@ jobs:
       - name: Install frontend dependencies
         working-directory: ./app
         run: |
-          rm -rf node_modules
+          rm -rf node_modules package-lock.json
           npm install
 
       - name: Install Tauri CLI