feat: initial Speedboard implementation

sitespeed.io web UI with Express/Pug/SQLite — port 3132.
Includes job queue, SSE live log, full metrics dashboard,
site history, CO2/axe/CWV sections, and Docker support.

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

Dockerfile

@@ -0,0 +1,36 @@
+# ─────────────────────────────────────────────────────────────────────────────
+# Speedboard Docker image
+#
+# Based on the official sitespeed.io image which already includes:
+#   - Node.js 20
+#   - Chrome & Firefox (headless)
+#   - Xvfb
+#   - sitespeed.io CLI
+# ─────────────────────────────────────────────────────────────────────────────
+FROM sitespeedio/sitespeed.io:latest
+
+WORKDIR /app
+
+# Copy speedboard app files
+COPY package.json ./
+RUN npm install --omit=dev
+
+COPY . .
+
+# Create persistent directories
+RUN mkdir -p /data/reports
+
+# Symlink reports dir into app folder
+RUN ln -sf /data/reports /app/reports
+
+# Runtime env
+ENV PORT=3132 \
+    IN_DOCKER=1 \
+    # sitespeed.io is already installed at /usr/local/lib/node_modules/sitespeed.io/bin/sitespeed.js
+    # but we ship our own copy — point to the bundled one inside image
+    SITESPEED_BIN=/usr/local/lib/node_modules/sitespeed.io/bin/sitespeed.js \
+    NODE_ENV=production
+
+EXPOSE 3000
+
+CMD ["node", "app.js"]