build: stamp updatecheck.buildChannel in single-channel pipelines (Spec 079 US2)

Dockerfile stamps buildChannel=docker; build-windows-installer.ps1 stamps
buildChannel=windows-installer on both core and tray ldflags. The
release.yml matrix builds intentionally stay unstamped (one binary feeds
tarball + Homebrew + DMG, so any single value would be wrong for some
consumers) — a comment at the ldflags site documents this. Makefile/
build.sh/build.ps1/pr-build.yml stay unstamped: dev builds use heuristics.

Author: Dumbris

.github/workflows/release.yml

@@ -392,6 +392,12 @@ jobs:
           CGO_LDFLAGS: "-mmacosx-version-min=13.0"
         run: |
           VERSION=${GITHUB_REF#refs/tags/}
+          # NOTE (Spec 079): the updatecheck.buildChannel install-channel marker is
+          # intentionally NOT stamped here — this one matrix binary feeds the tarball,
+          # Homebrew, and DMG artifacts, so any single channel value would be wrong for
+          # some consumers. Those installs rely on runtime heuristics
+          # (internal/updatecheck/channel.go); only single-channel pipelines stamp it
+          # (Dockerfile -> docker, scripts/build-windows-installer.ps1 -> windows-installer).
           LDFLAGS="-s -w -X main.version=${VERSION} -X github.com/smart-mcp-proxy/mcpproxy-go/internal/httpapi.buildVersion=${VERSION}"
 
           # Determine clean binary name and build flags

Dockerfile

@@ -19,7 +19,7 @@ ARG COMMIT=unknown
 ARG BUILD_DATE=unknown
 RUN CGO_ENABLED=0 go build \
     -tags server \
-    -ldflags "-X main.version=${VERSION} -X main.commit=${COMMIT} -X main.date=${BUILD_DATE} -X github.com/smart-mcp-proxy/mcpproxy-go/internal/httpapi.buildVersion=${VERSION} -s -w" \
+    -ldflags "-X main.version=${VERSION} -X main.commit=${COMMIT} -X main.date=${BUILD_DATE} -X github.com/smart-mcp-proxy/mcpproxy-go/internal/httpapi.buildVersion=${VERSION} -X github.com/smart-mcp-proxy/mcpproxy-go/internal/updatecheck.buildChannel=docker -s -w" \
     -o /mcpproxy ./cmd/mcpproxy
 
 # Runtime stage

scripts/build-windows-installer.ps1

@@ -48,7 +48,7 @@ Write-Host "  Building mcpproxy.exe..." -ForegroundColor White
 $env:CGO_ENABLED = "0"
 $CoreBinary = Join-Path $BinDir "mcpproxy.exe"
 $CoreCmd = Join-Path $RepoRoot "cmd/mcpproxy"
-go build -buildvcs=false -ldflags "-s -w -X main.version=$Version -X github.com/smart-mcp-proxy/mcpproxy-go/internal/httpapi.buildVersion=$Version" -o $CoreBinary $CoreCmd
+go build -buildvcs=false -ldflags "-s -w -X main.version=$Version -X github.com/smart-mcp-proxy/mcpproxy-go/internal/httpapi.buildVersion=$Version -X github.com/smart-mcp-proxy/mcpproxy-go/internal/updatecheck.buildChannel=windows-installer" -o $CoreBinary $CoreCmd
 
 if ($LASTEXITCODE -ne 0) {
     Write-Host "  Failed to build mcpproxy.exe" -ForegroundColor Red
@@ -61,7 +61,7 @@ Write-Host "  Building mcpproxy-tray.exe..." -ForegroundColor White
 $env:CGO_ENABLED = "1"
 $TrayBinary = Join-Path $BinDir "mcpproxy-tray.exe"
 $TrayCmd = Join-Path $RepoRoot "cmd/mcpproxy-tray"
-go build -buildvcs=false -ldflags "-s -w -X main.version=$Version -X github.com/smart-mcp-proxy/mcpproxy-go/internal/httpapi.buildVersion=$Version -H windowsgui" -o $TrayBinary $TrayCmd
+go build -buildvcs=false -ldflags "-s -w -X main.version=$Version -X github.com/smart-mcp-proxy/mcpproxy-go/internal/httpapi.buildVersion=$Version -X github.com/smart-mcp-proxy/mcpproxy-go/internal/updatecheck.buildChannel=windows-installer -H windowsgui" -o $TrayBinary $TrayCmd
 
 if ($LASTEXITCODE -ne 0) {
     Write-Host "  Failed to build mcpproxy-tray.exe" -ForegroundColor Red