feat: initial SleepGuard implementation

Wake-on-demand proxy + agent system with SvelteKit dashboard.
Monorepo: shared types, proxy (Hono + http-proxy), agent (monitors + locks), web (SvelteKit SPA).

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

packages/agent/Dockerfile

@@ -0,0 +1,42 @@
+FROM node:22-slim AS base
+RUN corepack enable
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    procps \
+    && rm -rf /var/lib/apt/lists/*
+
+# --- Dependencies ---
+FROM base AS deps
+WORKDIR /app
+COPY package.json yarn.lock .yarnrc.yml ./
+COPY packages/shared/package.json packages/shared/
+COPY packages/agent/package.json packages/agent/
+RUN yarn install --immutable
+
+# --- Build shared ---
+FROM deps AS build-shared
+WORKDIR /app
+COPY packages/shared packages/shared
+RUN yarn workspace @sleepguard/shared build
+
+# --- Build agent ---
+FROM build-shared AS build-agent
+WORKDIR /app
+COPY packages/agent/tsconfig.json packages/agent/
+COPY packages/agent/src packages/agent/src
+RUN yarn workspace @sleepguard/agent build
+
+# --- Production ---
+FROM base AS production
+WORKDIR /app
+
+COPY package.json yarn.lock .yarnrc.yml ./
+COPY packages/shared/package.json packages/shared/
+COPY packages/agent/package.json packages/agent/
+RUN yarn workspaces focus @sleepguard/agent --production
+
+COPY --from=build-shared /app/packages/shared/dist packages/shared/dist
+COPY --from=build-agent /app/packages/agent/dist packages/agent/dist
+
+WORKDIR /app/packages/agent
+EXPOSE 48527
+CMD ["node", "dist/index.js"]