feat: add build binaries workflow for multi-platform releases

- Add workflow_dispatch trigger for manual binary builds
- Build for linux (amd64, arm64, arm/v7), darwin (amd64, arm64), windows (amd64)
- Package as tar.gz (Unix) and zip (Windows)
- Generate build summary with artifact sizes

.github/workflows/build-binaries.yml

+name: Build Binaries
+
+on:
+  workflow_dispatch:
+
+jobs:
+  build-frontend:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: pnpm/action-setup@v4.2.0
+        with:
+          version: 10
+      - uses: actions/setup-node@v6
+        with:
+          node-version: "22"
+          cache: pnpm
+          cache-dependency-path: "web/pnpm-lock.yaml"
+      - name: Get pnpm store directory
+        id: pnpm-cache
+        shell: bash
+        run: echo "STORE_PATH=$(pnpm store path)" >> $GITHUB_OUTPUT
+      - name: Setup pnpm cache
+        uses: actions/cache@v5
+        with:
+          path: ${{ steps.pnpm-cache.outputs.STORE_PATH }}
+          key: ${{ runner.os }}-pnpm-store-${{ hashFiles('web/pnpm-lock.yaml') }}
+          restore-keys: ${{ runner.os }}-pnpm-store-
+      - run: pnpm install --frozen-lockfile
+        working-directory: web
+      - name: Run frontend build
+        run: pnpm release
+        working-directory: web
+
+      - name: Upload frontend artifacts
+        uses: actions/upload-artifact@v6
+        with:
+          name: frontend-dist
+          path: server/router/frontend/dist
+          retention-days: 7
+
+  build-binaries:
+    needs: build-frontend
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        include:
+          - goos: linux
+            goarch: amd64
+            platform: linux/amd64
+          - goos: linux
+            goarch: arm64
+            platform: linux/arm64
+          - goos: linux
+            goarch: arm
+            goarm: "7"
+            platform: linux/arm/v7
+          - goos: darwin
+            goarch: amd64
+            platform: darwin/amd64
+          - goos: darwin
+            goarch: arm64
+            platform: darwin/arm64
+          - goos: windows
+            goarch: amd64
+            platform: windows/amd64
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions/setup-go@v6
+        with:
+          go-version: "1.25"
+          cache: true
+
+      - name: Download frontend artifacts
+        uses: actions/download-artifact@v7
+        with:
+          name: frontend-dist
+          path: server/router/frontend/dist
+
+      - name: Build binary
+        env:
+          GOOS: ${{ matrix.goos }}
+          GOARCH: ${{ matrix.goarch }}
+          GOARM: ${{ matrix.goarm }}
+          CGO_ENABLED: "0"
+        run: |
+          # Determine output file name
+          OUTPUT_NAME="memos"
+          if [ "${{ matrix.goos }}" = "windows" ]; then
+            OUTPUT_NAME="memos.exe"
+          fi
+          
+          # Build with optimizations
+          go build \
+            -trimpath \
+            -ldflags="-s -w -extldflags '-static'" \
+            -tags netgo,osusergo \
+            -o "build/${OUTPUT_NAME}" \
+            ./cmd/memos
+          
+          echo "Built: build/${OUTPUT_NAME}"
+          ls -lh build/
+
+      - name: Package binary
+        run: |
+          cd build
+          
+          # Create package name
+          PACKAGE_NAME="memos-${{ matrix.goos }}-${{ matrix.goarch }}"
+          if [ -n "${{ matrix.goarm }}" ]; then
+            PACKAGE_NAME="memos-${{ matrix.goos }}-${{ matrix.goarch }}v${{ matrix.goarm }}"
+          fi
+          
+          # Package based on OS
+          if [ "${{ matrix.goos }}" = "windows" ]; then
+            zip "${PACKAGE_NAME}.zip" memos.exe
+            echo "ARTIFACT_NAME=${PACKAGE_NAME}.zip" >> $GITHUB_ENV
+          else
+            tar czf "${PACKAGE_NAME}.tar.gz" memos
+            echo "ARTIFACT_NAME=${PACKAGE_NAME}.tar.gz" >> $GITHUB_ENV
+          fi
+          
+          ls -lh
+          echo "Package created: ${ARTIFACT_NAME}"
+
+      - name: Upload binary artifact
+        uses: actions/upload-artifact@v6
+        with:
+          name: ${{ env.ARTIFACT_NAME }}
+          path: build/${{ env.ARTIFACT_NAME }}
+          retention-days: 7
+
+  summary:
+    needs: build-binaries
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download all artifacts
+        uses: actions/download-artifact@v7
+        with:
+          path: artifacts
+          pattern: memos-*
+
+      - name: Generate build summary
+        run: |
+          echo "## Build Summary" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "**Branch:** \`${{ github.ref_name }}\`" >> $GITHUB_STEP_SUMMARY
+          echo "**Commit:** \`${{ github.sha }}\`" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "### Built Artifacts" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "| Platform | Artifact | Size |" >> $GITHUB_STEP_SUMMARY
+          echo "|----------|----------|------|" >> $GITHUB_STEP_SUMMARY
+          
+          cd artifacts
+          for dir in */; do
+            artifact=$(ls "$dir" 2>/dev/null | head -1)
+            if [ -n "$artifact" ]; then
+              size=$(du -h "$dir/$artifact" | cut -f1)
+              platform=$(echo "$artifact" | sed 's/memos-//;s/\.(tar\.gz|zip)$//')
+              echo "| \`$platform\` | \`$artifact\` | $size |" >> $GITHUB_STEP_SUMMARY
+            fi
+          done
+          
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "**Download:** Go to the workflow run summary to download artifacts." >> $GITHUB_STEP_SUMMARY