Build optimization: pre-built PM3 binaries, ARM64 CI, base image caching

Replace PM3 compile-from-source in pi-gen with pre-built tarball extraction
(saves 43-58 min). Merge stagePM3 into stageDangerousPi as 02-pm3-install
substage, renumber all subsequent substages. Switch CI PM3 build to native
ARM64 runner (ubuntu-24.04-arm64) eliminating QEMU overhead. Add weekly
base-image workflow for pre-baking stages 0-2. Support PM3_TARBALL,
BASE_IMAGE, and APT_PROXY env vars in build-image.sh.

Also includes prior Phase 5 work: theme system, design system integration,
component update system, OS updates, CI build pipeline, and test results.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ci/build-theme.sh

@@ -0,0 +1,100 @@
+#!/usr/bin/env bash
+# Build the theme component from the @dangerousthings/tokens package.
+# Generates token CSS files and packages them for distribution.
+#
+# Environment variables:
+#   OUTPUT_DIR         - where to write the tarball (default: ./dist)
+#   VERSION            - version string (default: read from VERSION file)
+#   DESIGN_SYSTEM_DIR  - path to dt-design-system monorepo
+#                        (default: ../dt-design-system relative to workspace)
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+WORKSPACE="${SCRIPT_DIR}/.."
+OUTPUT_DIR="${OUTPUT_DIR:-${WORKSPACE}/dist}"
+VERSION="${VERSION:-$(cat "${WORKSPACE}/VERSION" 2>/dev/null || echo "0.1.0")}"
+DESIGN_SYSTEM_DIR="${DESIGN_SYSTEM_DIR:-$(realpath "${WORKSPACE}/../dt-design-system")}"
+
+echo "=== Dangerous Pi Theme Build ==="
+echo "Version:       ${VERSION}"
+echo "Design system: ${DESIGN_SYSTEM_DIR}"
+
+if [ ! -d "$DESIGN_SYSTEM_DIR" ]; then
+    echo "Error: dt-design-system not found at ${DESIGN_SYSTEM_DIR}"
+    echo "Set DESIGN_SYSTEM_DIR to the monorepo path"
+    exit 1
+fi
+
+# Build tokens to generate CSS
+cd "$DESIGN_SYSTEM_DIR"
+npm ci --production=false
+npm run build:tokens
+
+# Package theme CSS files
+STAGING="/tmp/theme-staging/theme"
+rm -rf /tmp/theme-staging
+
+BRANDS=("dt" "classic" "supra")
+for brand in "${BRANDS[@]}"; do
+    CSS_FILE="${DESIGN_SYSTEM_DIR}/packages/tokens/dist/css/${brand}.css"
+    if [ -f "$CSS_FILE" ]; then
+        mkdir -p "${STAGING}/${brand}"
+        cp "$CSS_FILE" "${STAGING}/${brand}/tokens.css"
+
+        # Read brand metadata from the generated CSS or tokens
+        cat > "${STAGING}/${brand}/theme.json" << TJEOF
+{
+  "id": "${brand}",
+  "supportsModes": ["dark", "light", "auto"],
+  "defaultMode": "dark"
+}
+TJEOF
+    else
+        echo "Warning: ${CSS_FILE} not found, skipping ${brand}"
+    fi
+done
+
+# Add brand metadata from tokens package if available
+TOKENS_INDEX="${DESIGN_SYSTEM_DIR}/packages/tokens/dist/index.js"
+if [ -f "$TOKENS_INDEX" ]; then
+    # Extract brand names/descriptions from the built tokens
+    node -e "
+const tokens = require('${TOKENS_INDEX}');
+const brands = Object.values(tokens.brands || {}).map(b => ({
+  id: b.id, name: b.name, description: b.description,
+  supportsModes: ['dark', 'light', 'auto'], defaultMode: 'dark'
+}));
+require('fs').writeFileSync('/tmp/theme-staging/theme/themes.json',
+  JSON.stringify({ schema_version: 1, themes: brands }, null, 2));
+" 2>/dev/null || echo '{"schema_version": 1, "themes": []}' > "${STAGING}/themes.json"
+else
+    # Fallback: generate registry from what we packaged
+    cat > "${STAGING}/themes.json" << REOF
+{
+  "schema_version": 1,
+  "themes": [
+    {"id": "dt", "name": "Dangerous Things", "description": "Official DT brand", "supportsModes": ["dark", "light", "auto"], "defaultMode": "dark"},
+    {"id": "classic", "name": "Classic Cyberpunk", "description": "Original dark navy aesthetic", "supportsModes": ["dark", "light", "auto"], "defaultMode": "dark"},
+    {"id": "supra", "name": "VivoKey Supra", "description": "Material Design 3 with VivoKey blue", "supportsModes": ["dark", "light", "auto"], "defaultMode": "dark"}
+  ]
+}
+REOF
+fi
+
+cat > "${STAGING}/COMPONENT_VERSION" << EOF
+{
+  "component_id": "theme",
+  "version": "${VERSION}",
+  "build_date": "$(date -u +"%Y-%m-%dT%H:%M:%SZ")",
+  "tokens_package_version": "$(node -p "require('${DESIGN_SYSTEM_DIR}/packages/tokens/package.json').version" 2>/dev/null || echo "unknown")"
+}
+EOF
+
+mkdir -p "$OUTPUT_DIR"
+TARBALL="theme-${VERSION}.tar.gz"
+cd /tmp/theme-staging
+tar -czf "${OUTPUT_DIR}/${TARBALL}" theme/
+echo "✅ Built: ${OUTPUT_DIR}/${TARBALL}"
+
+rm -rf /tmp/theme-staging