feat: Add build scripts and runtime config support

Backend:
- Add setup-backend.sh/bat for one-click backend setup
- Fix test_auth.py mock settings (JWT_EXPIRE_HOURS)
- Fix test_excel_export.py TEMPLATE_DIR reference

Frontend:
- Add config.json for runtime API URL configuration
- Add init.js and settings.js for config loading
- Update main.js to load config from external file
- Update api.js to use dynamic API_BASE_URL
- Update all pages to initialize config before API calls
- Update package.json with extraResources for config

Build:
- Add build-client.sh/bat for packaging Electron + Sidecar
- Add build-all.ps1 PowerShell script with -ApiUrl parameter
- Add GitHub Actions workflow for Windows builds
- Add scripts/README.md documentation

This allows IT to configure backend URL without rebuilding.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/build-windows.yml

@@ -0,0 +1,155 @@
+name: Build Windows Client
+
+on:
+  workflow_dispatch:  # 手動觸發
+    inputs:
+      api_url:
+        description: 'Backend API URL (e.g., http://192.168.1.100:8000/api)'
+        required: false
+        default: 'http://localhost:8000/api'
+        type: string
+      whisper_model:
+        description: 'Whisper model size'
+        required: false
+        default: 'medium'
+        type: choice
+        options:
+          - tiny
+          - base
+          - small
+          - medium
+          - large
+  push:
+    tags:
+      - 'v*'  # 推送版本 tag 時自動觸發
+
+jobs:
+  build-sidecar:
+    name: Build Sidecar (Python → exe)
+    runs-on: windows-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+          cache: 'pip'
+          cache-dependency-path: sidecar/requirements.txt
+
+      - name: Install sidecar dependencies
+        working-directory: sidecar
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r requirements.txt
+          pip install pyinstaller
+
+      - name: Build sidecar with PyInstaller
+        working-directory: sidecar
+        run: |
+          pyinstaller `
+            --onedir `
+            --name transcriber `
+            --distpath dist `
+            --workpath build `
+            --noconfirm `
+            --clean `
+            --console `
+            --hidden-import=faster_whisper `
+            --hidden-import=ctranslate2 `
+            --hidden-import=huggingface_hub `
+            --hidden-import=tokenizers `
+            --hidden-import=onnxruntime `
+            --hidden-import=opencc `
+            --hidden-import=pydub `
+            --hidden-import=numpy `
+            --hidden-import=av `
+            --collect-data=onnxruntime `
+            --collect-data=faster_whisper `
+            transcriber.py
+
+      - name: Upload sidecar artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: sidecar-windows
+          path: sidecar/dist/transcriber/
+          retention-days: 1
+
+  build-electron:
+    name: Build Electron App
+    needs: build-sidecar
+    runs-on: windows-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+          cache-dependency-path: client/package-lock.json
+
+      - name: Download sidecar artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: sidecar-windows
+          path: sidecar/dist/transcriber/
+
+      - name: Install client dependencies
+        working-directory: client
+        run: npm ci
+
+      - name: Update config.json with API URL
+        working-directory: client
+        shell: pwsh
+        run: |
+          $configPath = "config.json"
+          $apiUrl = "${{ inputs.api_url || 'http://localhost:8000/api' }}"
+
+          if (Test-Path $configPath) {
+            $config = Get-Content $configPath -Raw | ConvertFrom-Json
+            $config.apiBaseUrl = $apiUrl
+            $config | ConvertTo-Json -Depth 10 | Set-Content $configPath -Encoding UTF8
+            Write-Host "Updated API URL to: $apiUrl"
+          }
+
+      - name: Build Electron app
+        working-directory: client
+        run: npm run build -- --win
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Upload Windows build
+        uses: actions/upload-artifact@v4
+        with:
+          name: meeting-assistant-windows
+          path: |
+            client/dist/*.exe
+            client/dist/*.zip
+          retention-days: 30
+
+  release:
+    name: Create Release
+    needs: build-electron
+    runs-on: ubuntu-latest
+    if: startsWith(github.ref, 'refs/tags/v')
+
+    steps:
+      - name: Download Windows build
+        uses: actions/download-artifact@v4
+        with:
+          name: meeting-assistant-windows
+          path: dist/
+
+      - name: Create Release
+        uses: softprops/action-gh-release@v1
+        with:
+          files: dist/*
+          draft: true
+          generate_release_notes: true
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}