feat: L0b bootstrap scripts + L1 Go CLI structure

L0b (factory bootstrap):
- bootstrap.ps1 (Windows): pre-checks, interactive config, clone .factory, home.toml
- bootstrap.sh (Linux/Mac): same functionality for bash
- Idempotent re-run with home.toml verification

L1 (Go CLI):
- factory.yaml: manifest schema with components, deps, health-checks
- cmd/factory: Cobra CLI (install/update/status/diagnose)
- pkg/config: home.toml reader
- pkg/manifest: factory.yaml parser + topological sort
- pkg/health: health-check logic (file/dir/mcp_tool/command)

Scripts:
- build.sh: cross-compile for linux/win/darwin × amd64/arm64
- build.ps1: PowerShell cross-compile

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/build.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+# Cross-compile factory for all platforms
+
+set -euo pipefail
+
+cd "$(dirname "$0")/.."
+VERSION=${VERSION:-"0.1.0"}
+DIST_DIR="dist"
+
+echo "Building factory v$VERSION..."
+
+mkdir -p "$DIST_DIR"
+
+# Cross-compile targets
+declare -A TARGETS=(
+    ["linux-amd64"]="linux/amd64"
+    ["linux-arm64"]="linux/arm64"
+    ["windows-amd64"]="windows/amd64"
+    ["windows-arm64"]="windows/arm64"
+    ["darwin-amd64"]="darwin/amd64"
+    ["darwin-arm64"]="darwin/arm64"
+)
+
+for name in "${!TARGETS[@]}"; do
+    goos="${name%%-*}"
+    goarch="${name##*-}"
+    platform="${TARGETS[$name]}"
+    output="$DIST_DIR/factory-$goos-$goarch"
+    [[ "$goos" == "windows" ]] && output="$output.exe"
+
+    echo "  → $name ($platform)"
+
+    GOOS="$goos" GOARCH="$goarch" \
+    CGO_ENABLED=0 \
+    go build -ldflags="-s -w -X main.Version=$VERSION" \
+        -o "$output" ./cmd/factory
+done
+
+echo ""
+echo "✓ Built to $DIST_DIR/"
+ls -lh "$DIST_DIR/"