Fix Windows build: use lld linker instead of MinGW ld

MinGW's ld runs out of memory (exit code 5) linking DuckDB's large
static library. Switch to LLVM's lld which handles large binaries
efficiently.

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

Author: wesm

.github/workflows/release.yml

@@ -154,7 +154,7 @@ jobs:
         uses: msys2/setup-msys2@4f806de0a5a7294ffabaff804b38a9b435a73bda # v2.30.0
         with:
           msystem: MINGW64
-          install: mingw-w64-x86_64-gcc
+          install: mingw-w64-x86_64-gcc mingw-w64-x86_64-lld
 
       - name: Build
         shell: pwsh
@@ -167,7 +167,7 @@ jobs:
           $VERSION = "${{ github.ref_name }}".TrimStart("v")
 
           New-Item -ItemType Directory -Force -Path dist | Out-Null
-          $LDFLAGS = "-s -w -X github.com/wesm/msgvault/cmd/msgvault/cmd.Version=v${VERSION} -extldflags '-Wl,--no-keep-memory'"
+          $LDFLAGS = "-s -w -X github.com/wesm/msgvault/cmd/msgvault/cmd.Version=v${VERSION} -extldflags '-fuse-ld=lld'"
           go build -tags fts5 -trimpath -ldflags="$LDFLAGS" -o dist/msgvault.exe ./cmd/msgvault
           if ($LASTEXITCODE -ne 0) { throw "Build failed" }