Add Phase 0 build verification gate (T-004)

scripts/verify_phase0.sh

@@ -0,0 +1,63 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT_DIR"
+
+if python3 --version >/dev/null 2>&1; then
+  PYTHON=python3
+elif python --version >/dev/null 2>&1; then
+  PYTHON=python
+else
+  echo "ERROR: Python 3 is required." >&2
+  exit 2
+fi
+
+GO_PATH="$(go env GOPATH)"
+if command -v cygpath >/dev/null 2>&1; then
+  GO_PATH="$(cygpath -u "$GO_PATH")"
+fi
+GO_BIN="$GO_PATH/bin"
+if [ -x "$GO_BIN/go1.20.14" ] || [ -x "$GO_BIN/go1.20.14.exe" ]; then
+  export PATH="$GO_BIN:$PATH"
+fi
+
+mkdir -p dist
+
+echo "==> Sync root workspace"
+GOTOOLCHAIN=go1.25.0 go work sync
+
+echo "==> Validate harness governance"
+"$PYTHON" scripts/validate_agent_context.py
+"$PYTHON" -m unittest discover -s tests -p "test_*.py"
+"$PYTHON" scripts/validate_harness_governance.py
+
+echo "==> Validate core architecture boundary"
+"$PYTHON" scripts/check_core_boundaries.py --self-test
+"$PYTHON" scripts/check_core_boundaries.py
+
+echo "==> Validate Go and dependency pins"
+GOTOOLCHAIN=go1.20.14 "$PYTHON" scripts/check_go_versions.py
+
+echo "==> Vet and test core with Go 1.20.14"
+GOTOOLCHAIN=go1.20.14 GOWORK=off go -C core vet ./...
+GOTOOLCHAIN=go1.20.14 GOWORK=off go -C core test -count=1 ./...
+
+echo "==> Test and build modern target with Go 1.25.0"
+GOTOOLCHAIN=go1.25.0 GOWORK="$ROOT_DIR/go.work" CGO_ENABLED=0 \
+  go -C app-modern test -count=1 ./ui/gio ./platform/windows
+GOTOOLCHAIN=go1.25.0 GOWORK="$ROOT_DIR/go.work" CGO_ENABLED=0 \
+  GOOS=windows GOARCH=amd64 \
+  go -C app-modern build -trimpath -ldflags="-H=windowsgui" \
+  -o ../dist/SoftBox.exe ./cmd/softbox
+
+echo "==> Test and build Win7 target with Go 1.20.14"
+GOTOOLCHAIN=go1.20.14 GOWORK="$ROOT_DIR/app-win7/go.work" CGO_ENABLED=0 \
+  go -C app-win7 test -count=1 ./ui/gio ./platform/windows
+GOTOOLCHAIN=go1.20.14 GOWORK="$ROOT_DIR/app-win7/go.work" CGO_ENABLED=0 \
+  GOOS=windows GOARCH=amd64 \
+  go -C app-win7 build -trimpath -ldflags="-H=windowsgui" \
+  -o ../dist/SoftBox-win7.exe ./cmd/softbox
+
+echo "Phase 0 verification passed."