fix(ci): resolve actionlint shellcheck warnings and bump setup-node to v6

- Remove unused KEYCHAIN_PATH variable in release workflow
- Quote variable expansions to prevent globbing/word splitting (SC2086)
- Replace ls with find for non-alphanumeric filename safety (SC2012)
- Bump actions/setup-node from v4 to v6 in setup-tauri-build

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: pythoninthegrass

.github/actions/setup-tauri-build/action.yml

@@ -73,7 +73,7 @@ runs:
 
     - name: Setup Node.js
       if: inputs.mode == 'full'
-      uses: actions/setup-node@v4
+      uses: actions/setup-node@v6
       with:
         node-version: ${{ inputs.node-version }}
 

.github/workflows/release.yml

@@ -55,8 +55,7 @@ jobs:
           APPLE_CERTIFICATE_PASSWORD: ${{ secrets.APPLE_CERTIFICATE_PASSWORD }}
           KEYCHAIN_PASSWORD: ${{ secrets.KEYCHAIN_PASSWORD }}
         run: |
-          KEYCHAIN_PATH="$HOME/Library/Keychains/ci_signing.keychain-db"
-          echo $APPLE_CERTIFICATE | base64 --decode > certificate.p12
+          echo "$APPLE_CERTIFICATE" | base64 --decode > certificate.p12
           security create-keychain -p "$KEYCHAIN_PASSWORD" ci_signing.keychain
           security default-keychain -s ci_signing.keychain
           security unlock-keychain -p "$KEYCHAIN_PASSWORD" ci_signing.keychain

.github/workflows/test-local.yml

@@ -20,13 +20,15 @@ jobs:
       - name: Install Deno
         run: |
           curl -fsSL https://deno.land/install.sh | sh
-          echo "$HOME/.deno/bin" >> $GITHUB_PATH
+          echo "$HOME/.deno/bin" >> "$GITHUB_PATH"
 
       - name: Check Deno formatting
-        run: $HOME/.deno/bin/deno fmt --check
+        run: |
+          "$HOME/.deno/bin/deno" fmt --check
 
       - name: Run Deno lint
-        run: $HOME/.deno/bin/deno lint
+        run: |
+          "$HOME/.deno/bin/deno" lint
 
   # Vitest unit tests
   vitest-tests:
@@ -87,7 +89,7 @@ jobs:
           fi
           echo "Working directory: $(pwd)"
           echo "Node version: $(node --version)"
-          ls -la app/frontend/ | head -5
+          find app/frontend/ -maxdepth 1 | head -5
 
       - name: Install frontend dependencies
         working-directory: ./app/frontend